Remove "semi-safe" term.

Based on comments from [this reddit
thread](http://www.reddit.com/r/rust/comments/2lapta/rusqlite_ergonomic_semisafe_bindings_to_sqlite/).

README.md

@@ -2,7 +2,7 @@
 
 [![Build Status](https://api.travis-ci.org/jgallagher/rusqlite.svg?branch=master)](https://travis-ci.org/jgallagher/rusqlite)
 
-Rusqlite is an ergonomic, semi-safe wrapper for using SQLite from Rust. It attempts to expose
+Rusqlite is an ergonomic wrapper for using SQLite from Rust. It attempts to expose
 an interface similar to [rust-postgres](https://github.com/sfackler/rust-postgres). View the full
 [API documentation](http://www.rust-ci.org/jgallagher/rusqlite/doc/rusqlite/).
 
@@ -53,54 +53,20 @@ fn main() {
 }
 ```
 
-## "Semi-Safe"?
+### Design of SqliteRows and SqliteRow
-
-There are two parts of Rusqlite that are not as safe as a proper Rust library should be. Both are
-related to the API of SQLite itself. SQLite is a phenomenal piece of software, but its API does
-not mesh very well with the ownership semantics of Rust.
-
-### Semi-Safe: SqliteConnection
-
-The first form of "semi-safeness" is the `SqliteConnection` handle itself. The underlying C handle,
-[sqlite3](https://www.sqlite.org/c3ref/sqlite3.html), has at least two pieces of internal state
-that can be affected across multiple SQLite calls: the last insertion ID (retrieved via
-[sqlite3_last_insert_rowid()](https://www.sqlite.org/c3ref/last_insert_rowid.html)) and a detailed
-error message for the most recent error (retrieved via
-[sqlite3_errmsg()](https://www.sqlite.org/c3ref/errcode.html)). As mentioned by the documentation
-for both functions, this internal state is inherently not thread safe. Even if SQLite is using
-locks to provide thread safety (which is the default), multiple threads accessing the same
-connection can cause undefined behavior with these functions (e.g., if both threads insert a row
-and then both threads try to get the last insertion row ID, both threads will get the same row ID
-of whichever insertion happened second).
-
-This could be addressed in Rust by making any calls that might affect the internal state of the
-connection borrow the connection mutably until they complete. This is the tactic taken by
-[rust-sqlite3](https://github.com/dckc/rust-sqlite3), and it is the most correct option from a
-Rust point of view. However, it causes problems with things like transactions. Therefore,
-Rusqlite's `SqliteConnection` uses a [RefCell](http://doc.rust-lang.org/std/cell/) internally
-to allow the connection to be shared even though it is mutable.
-
-The practical implication of this is that `SqliteConnection` is *not* thread-safe, and must not be
-used from multiple threads at the same time, but you must enforce this with little-to-no help from
-the type system. If you use a single connection from multiple threads, you may encounter a panic
-(from the underlying RefCell), or you may introduce data races (as described above with the last
-insertion ID or error message).
-
-### Semi-Safe: SqliteRows and SqliteRow
 
 To retrieve the result rows from a query, SQLite requires you to call
 [sqlite3_step()](https://www.sqlite.org/c3ref/step.html) on a prepared statement. You can only
 retrieve the values of the "current" row. From the Rust point of view, this means that each row
-is only valid until the next row is fetched. Again,
+is only valid until the next row is fetched.  [rust-sqlite3](https://github.com/dckc/rust-sqlite3)
-[rust-sqlite3](https://github.com/dckc/rust-sqlite3) solves this the correct way with lifetimes.
+solves this the correct way with lifetimes.  However, this means that the result rows do not
-However, this means that the result rows do not satisfy the
+satisfy the [Iterator](http://doc.rust-lang.org/std/iter/trait.Iterator.html) trait, which means
-[Iterator](http://doc.rust-lang.org/std/iter/trait.Iterator.html) trait, which means you cannot
+you cannot (as easily) loop over the rows, or use many of the helpful Iterator methods like `map`
-(as easily) loop over the rows, or use many of the helpful Iterator methods like `map` and
+and `filter`.
-`filter`.
 
-Instead, Rusqlite's `SqliteRows` handle does conform to `Iterator`. It performs checks at runtime
+Instead, Rusqlite's `SqliteRows` handle does conform to `Iterator`. It ensures safety by
-to ensure you do not try to retrieve the values of a "stale" row, and will panic if you do so.
+performing checks at runtime to ensure you do not try to retrieve the values of a "stale" row, and
-A specific example that will panic:
+will panic if you do so. A specific example that will panic:
 
 ```rust
 fn bad_function_will_panic(conn: &SqliteConnection) -> SqliteResult<i64> {

src/lib.rs

@@ -1,4 +1,4 @@
-//! Rusqlite is an ergonomic, semi-safe wrapper for using SQLite from Rust. It attempts to expose
+//! Rusqlite is an ergonomic wrapper for using SQLite from Rust. It attempts to expose
 //! an interface similar to [rust-postgres](https://github.com/sfackler/rust-postgres).
 //!
 //! ```rust
@@ -591,10 +591,10 @@ pub struct SqliteRow<'stmt> {
 impl<'stmt> SqliteRow<'stmt> {
     /// Get the value of a particular column of the result row.
     ///
-    /// Note that `SqliteRow` falls into the "semi-safe" category of rusqlite. When you are
+    /// Note that `SqliteRow` can panic at runtime if you use it incorrectly. When you are
     /// retrieving the rows of a query, a row becomes stale once you have requested the next row,
-    /// and the values can no longer be retrieved. In general (when using a loop over the rows, for
+    /// and the values can no longer be retrieved. In general (when using looping over the rows,
-    /// example) this isn't an issue, but it means you cannot do something like this:
+    /// for example) this isn't an issue, but it means you cannot do something like this:
     ///
     /// ```rust,no_run
     /// # use rusqlite::{SqliteConnection, SqliteResult};