Previously, sound failed due to errors with hardfp abi build
instructions. As the problem couldn't be found, the softfp
compatible abi was chosen instead.

This move will cause a small performance overhead, but due to the
abi being armeabi-v7a, the internal calculations will still be done
using the FPU.

We also fix some issues with ABI information passing. However, the
fixes aren't sufficient to get sound working.

The patch also fixes an issue with the gitignore file.

Before, android_version.h got changed at every new commit. Now, we
only change it with new minetest releases. Analogous to how cmake
does it,  we add an android_version_githash.h file that communicates
the git hash to C++ code.

Also, unify VERS_MAJOR, VERS_MINOR and VERS_PATCH variable
calculation inside the whole makefile.

Previously, if you did `make envpaths` (as described in README.android), the new file got listed by git as new file.

Specifically, the added rule matches .kate-swp files.

Uses system provided libgmp if found, if not it falls back to mini-gmp.

If CMake is run and Doxygen is found, add a make target called "doc",
which builds API documention in doc/html. This target is not included
in the default "all" target, you have to explicitly run "make doc" to
generate the documentation.

If graphviz is installed, in particular, if the "dot" binary is found,
doxygen is configured to generate various kinds of diagrams. Note that
due to this, the first run of doxygen can take a while.

There have been plenty of ppl involved in creating this version.
I don't wanna mention names as I'm sure I'd forget someone so I
just tell where help has been done:
- The partial android versions done by various ppl
- Testing on different android devices
- reviewing code (especially the in core changes)
- testing controls
- reviewing texts

A big thank you to everyone helping this to be completed!

On the lua side, notably minetest.env:<function>(<args>) should now
be replaced by minetest.<function>(<args>).
The old way is and will stay supported for a long time.

Also:
Update and clean up lua_api.txt (by celeron55)
Move EnvRef to lua and remove add_rat and add_firefly (by kahrl)
Add separate src/util/CMakeLists.txt, other minor fixes (by kahrl)

Also add a menuheader, menusplash, menufooter_clouds, and allow HD menu footers.
And finally don't git-ignore textures/base/.

New map generator added (and SQLite, messed up the commits at that time...) (import from temporary git repo)

--HG--
extra : rebase_source : 7260636295d9068fbeeddf4143c89f2b8a91446c