mdbx-build: rearrange source files, rework CMakeLists.txt and refine GNUMakefile (squashed).

Change-Id: Id73d346695011dab2f670bb9e6293a1e5a1835ca

src/config.h.in

@@ -0,0 +1,53 @@
+/* This is CMake-template for libmdbx's config.h
+ ******************************************************************************/
+
+/* *INDENT-OFF* */
+/* clang-format off */
+
+#cmakedefine LTO_ENABLED
+#cmakedefine MDBX_USE_VALGRIND
+#cmakedefine ENABLE_GPROF
+#cmakedefine ENABLE_GCOV
+#cmakedefine ENABLE_ASAN
+#cmakedefine MDBX_FORCE_ASSERTIONS
+
+/* Common */
+#cmakedefine01 MDBX_TXN_CHECKOWNER
+#cmakedefine MDBX_TXN_CHECKPID_AUTO
+#ifndef MDBX_TXN_CHECKPID_AUTO
+#cmakedefine01 MDBX_TXN_CHECKPID
+#endif
+#cmakedefine01 MDBX_BUILD_SHARED_LIBRARY
+#cmakedefine MDBX_LOCKING_AUTO
+#ifndef MDBX_LOCKING_AUTO
+#cmakedefine MDBX_LOCKING @MDBX_LOCKING@
+#endif
+#cmakedefine MDBX_TRUST_RTC_AUTO
+#ifndef MDBX_TRUST_RTC_AUTO
+#cmakedefine01 MDBX_TRUST_RTC
+#endif
+
+/* Windows */
+#cmakedefine01 MDBX_CONFIG_MANUAL_TLS_CALLBACK
+#cmakedefine01 MDBX_AVOID_CRT
+
+/* MacOS & iOS */
+#cmakedefine01 MDBX_OSX_SPEED_INSTEADOF_DURABILITY
+
+/* POSIX */
+#cmakedefine01 MDBX_DISABLE_GNU_SOURCE
+#cmakedefine MDBX_USE_OFDLOCKS_AUTO
+#ifndef MDBX_USE_OFDLOCKS_AUTO
+#cmakedefine01 MDBX_USE_OFDLOCKS
+#endif
+
+/* Build Info */
+#cmakedefine MDBX_BUILD_TIMESTAMP "@MDBX_BUILD_TIMESTAMP@"
+#cmakedefine MDBX_BUILD_TARGET "@MDBX_BUILD_TARGET@"
+#cmakedefine MDBX_BUILD_TYPE "@MDBX_BUILD_TYPE@"
+#cmakedefine MDBX_BUILD_COMPILER "@MDBX_BUILD_COMPILER@"
+#cmakedefine MDBX_BUILD_FLAGS "@MDBX_BUILD_FLAGS@"
+#cmakedefine MDBX_BUILD_SOURCERY @MDBX_BUILD_SOURCERY@
+
+/* *INDENT-ON* */
+/* clang-format on */