f7d65091 introduces error when no endian.h found in the system.

Since "CHECK_INCLUDE_FILE" returns empty string instead of "0", when
"cmake_config.h" is generated it has "#define CMAKE_HAVE_ENDIAN_H " line.
Later we have "#define HAVE_ENDIAN_H CMAKE_HAVE_ENDIAN_H" in the
"config.h", an thus "HAVE_ENDIAN_H" is also empty sting. Because of
this, "#if HAVE_ENDIAN_H" is incorrect preprocessor directive.

Signed-off-by: Craig Robbins <kde.psych@gmail.com>

serialize.h: use machine native byte swapping if available, fall-back to previous generic method if not (supported for GCC using endian.h, detection done in cmake) write/readARGB8() - just write 32-bit color in one op, instead of 4 1-byte ops cleanup: removed unneeded buffer init for some serialize-out functions use a #define for the fixed point factor in read/writeF1000()

nodemetadata.cpp, nodetimer.cpp
	optimzation: simpler deserialize node position method

staticobject.cpp:
	cleanup: use util/serialize.h inlines instead of its own de/serialization

serialize.cpp:
	minor optimization/cleanup: avoid generation of unneeded string temporary

CMakeLists.txt, cmake_config.h.in: detection of endian.h

config.h: added HAVE_ENDIAN_H

Commits due to feedback squashed

Signed-off-by: Craig Robbins <kde.psych@gmail.com>

- Don't create and cache an extruded mesh for every (non-node) item.
  Instead use a single one per image resolution.

- For cubic nodes reuse a single wield mesh too

- Improve lighting of the wielded item

- Increase far value of wield mesh scene camera, fixes #1770

- Also includes some minor refactorings of Camera and GenericCAO.

This also cleans up settings a bit

Add ZLIBWAPI_DLL and LEVELDB_DLL CMake options Remove legacy MINGWM10_DLL CMake option Update 32-bit buildbot (OpenAL updated, zlib updated) Change build directory for buildbots to '_build' to prevent removal of Android build files Use -win64 suffix for 64-bit Windows builds Fixes #1476

Revert "Fix library link order"
This reverts commit b743dcb9.

Add (experimental) support for topbottom as well as sidebyside 3d mode

  -add client states to avoid server sending data to uninitialized clients
  -don't show uninitialized clients to other players
  -propper client disconnect handling
Minor comment fixes in server
Minor bugfixes in connection
  -improved peer id calculation
  -honor NDEBUG flag
  -improved disconnect handling
  -increased initial send window
Remove some dead code

because cmake is unable to parse it's own lists properly

This can solve numerous problems such as:
http://www.cmake.org/Bug/view.php?id=13959
http://www.cmake.org/Bug/view.php?id=14601

If pkg-config or freetype2.pc is not found, then fall back to the
FindFreetype.cmake module logic.

Restrict to UNIX since I only tested it here.

Move most of the media-related code in client.cpp into a new class
ClientMediaDownloader (clientmedia.cpp, clientmedia.h). Among other
things, this class does the following things:

- Download [remote_server][sha1] instead of [remote_server][name]. This
is to support servers that provide the same file name with different
contents.
- Initially fetch [remote_server]index.mth. This file should follow the
Minetest Hashset format (currently version 1) and contain a list of SHA1
hashes that exist on the server.
- The list of needed SHA1s is uploaded (via HTTP POST) when index.mth is
requested, so servers can optionally narrow down the list to the needs
of the client.
- If index.mth is missing (HTTP response code 404), we enter compat mode,
fetching [remote_server][name] as before this commit.
- remote_server can now contain multiple servers, separated by commas.
The downloader code attempts to split requests between the different
servers, as permitted by each server's index.mth. If one server claims
to have a file but actually doesn't (or something fails), we ask a
different server that also claims to have it.
- As before, when none of the remote servers provide a particular
file, we download it via the conventional method, i.e. using
the minetest protocol: TOSERVER_REQUEST_MEDIA / TOCLIENT_MEDIA.
- Bugfix: Every downloaded file's SHA1 is now verified against the SHA1
announced by the minetest server (before loading it and inserting it
into the file cache).
- Bugfix: Only send TOSERVER_RECEIVED_MEDIA when we actually have all
media. This should fix #863.

Add curl_parallel_limit setting that will replace media_fetch_threads in
a later commit.

Fix a typo in MutexedQueue::pop_back() that made it impossible to compile
code that used this function. (Noticed this while implementing httpfetch.)