Include mg_decoration.h, mg_ore.h from emerge.cpp to fix warnings
Cleanup and (mostly) document util/string.h and (very) minor refactoring

Updated: Incorporated feedback from 'kahrl'
Updated: Moved MinetestApp::boolToCStr() from game.cpp into string.h renaming it bool_to_cstr()
Keep all the games directory when installing

If builder have games in games directory, we must zip these games.
For minetest_game, the new config files were not zip before. In the futur, if minetest_game has new files, they will be zip without any modification.
Build minetest for windows 64 in fedora 20
Merge remote-tracking branch 'minetest/master'