Use wide_to_utf8 and utf8_to_wide instead of wide_to_narrow and narrow_to_wide at almost all places.
Only exceptions: test functions for narrow conversion, and chat, which is done in a separate commit.

Also fix UTF-8 inner byte bounds and make unittest for case this fixes.

Also count multibyte sequences as "one" character.
Adds unittest for the bug reporter's case.
Fixes #2796.

No freezing when inbuf_size doesn't decrease over time.

While utf8_to_wide works well, wide_to_utf8 is quite broken
on android, for some reason.

Adds everything needed for SRP (and everything works too),
but still deactivated, as protocol v25 init packets aren't final yet.
Can be activated by changing the LATEST_PROTOCOL_VERSION header to 25
inside networkprotocol.h.

-> Round negative numbers correctly CMakeLists.txt
-> Link Json with the static run-time library

Change types for passed password from wstring to string, which removes converting
back and forth in most cases. Move the narrow_to_wide conversion, where its neccessary,
closer to irrlicht. Remove trailing spaces in guiPasswordChange.cpp. Make parameters for
translatePassword passed as const reference.

Add core.clear_registered_schematics() and refactor schematics somewhat

  * Combine client and server man pages.
  * Update unit test options and available databases in man page.
  * Add `--worldname` to man page.
  * Fix a bunch of places where `"Minetest"` was used directly instead of `PROJECT_NAME`.
  * Disable server build by default on all operating systems.
  * Make `ENABLE_FREETYPE` not fail if FreeType isn't found.
  * Enable LevelDB, Redis, and FreeType detection by default.
  * Remove the `VERSION_PATCH_ORIG` hack.
  * Add option to search for and use system JSONCPP.
  * Remove broken LuaJIT version detection.
  * Rename `DISABLE_LUAJIT` to `ENABLE_LUAJIT`.
  * Rename `minetest_*` variables in `version.{h,cpp}` to `g_*`.
  * Clean up style of CMake files.

For usages of assert() that are meant to persist in Release builds (when NDEBUG is defined), replace those usages with persistent alternatives

* Ensure converted string is NUL terminated
* Restore logic to that used prior to 9e2a9b55

wrapDegrees() (renamed to modulo360f)
wrapDegrees_0_360
wrapDegrees_180

Minor errors were present in previous versions; see issue #2328

This greatly reduce the number of std::list generated by caching the result, which is always constant for each radius selected.
In the callgrind map, you will see original:
  * 3.3M calls to std::list for 9700 calls to getFacePositions
In the modified version, you will see:
  * 3.3K calls to std::list for 6900 call to getFacePositions
Callgrind map is here: #2321

it's a huge performance improvement to l_find_node_near

Change must_reflow to a deque
Add overload for MapBlock::raiseModified that takes a const char*. This is a speed improvement.
Comment out unused variable
Optimisations to block offset calculations