mdbx: release v0.11.5

The stable release with the hotfix/workaround for a flaw of Linux 4.19 (at least) unified page/buffer cache.
See [issue#269](https://github.com/erthink/libmdbx/issues/269) for more information.

Acknowledgements:
-----------------

 - [Simon Leier](https://github.com/leisim) for reporting and testing.
 - [Kai Wetlesen](https://github.com/kaiwetlesen) for [RPMs](http://copr.fedorainfracloud.org/coprs/kwetlesen/libmdbx/).
 - [Tullio Canepa](https://github.com/canepat) for reporting C++ API issue and contributing.

Fixes:
------

 - [Added workaround](https://github.com/erthink/libmdbx/issues/269) for a flaw of Linux 4.19 (at least) unified page/buffer cache.
 - [Fixed/Reworked](https://github.com/erthink/libmdbx/pull/270) move-assignment operators for "managed" classes of C++ API.
 - Fixed potential `SIGSEGV` while open DB with overrided non-default page size.
 - [Made](https://github.com/erthink/libmdbx/issues/267) `mdbx_env_open()` idempotence in failure cases.
 - Refined/Fixed pages reservation inside `mdbx_update_gc()` to avoid non-reclamation in a rare cases.
 - Fixed typo in a retained space calculation for the hsr-callback.

Minors:
-------

 - Reworked functions for meta-pages, split-off non-volatile.
 - Disentangled C11-atomic fences/barriers and pure-functions (with `__attribute__((__pure__))`) to avoid compiler misoptimization.
 - Fixed hypotetic unaligned access to 64-bit dwords on ARM with `__ARM_FEATURE_UNALIGNED` defined.
 - Reasonable paranoia that makes clarity for code readers.
 - Minor fixes Doxygen references, comments, descriptions, etc.

Signed-off-by: Леонид Юрьев (Leonid Yuriev) <leo@yuriev.ru>

.github/actions/spelling/expect.txt

@@ -209,6 +209,7 @@ condpair
 config
 constexpr
 constmeta
+coprs
 copyable
 copydetails
 copydoc
@@ -512,6 +513,7 @@ FCXX
 fd
 fdatasync
 featuredarticles
+fedorainfracloud
 fedotov
 FEEDNAME
 feof
@@ -666,6 +668,7 @@ hlp
 HOfynt
 hostid
 HOSTUUID
+hotfix
 hpp
 hppa
 hpux
@@ -791,6 +794,7 @@ jgamble
 jmp
 jpg
 json
+kaiwetlesen
 kbuf
 Kerollmops
 kerr
@@ -820,6 +824,7 @@ Kuntze
 kurt
 kuznik
 kval
+kwetlesen
 Lanfranchi
 largedata
 largepage
@@ -1490,6 +1495,7 @@ rpath
 rpb
 rpcc
 rpid
+RPMs
 rqest
 rr
 RRF
@@ -1934,6 +1940,7 @@ wdm
 webassembly
 webclient
 WERROR
+Wetlesen
 WEXITSTATUS
 WEXTRA
 whitelist