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