Disable preload_item_visuals by default

This can delay connections by several minutes.
Formspec escape fixed seen in world creation menu
Move #includes from version.h to version.cpp
Make faces shading correct for all possible modes.
Skip shading for lightsources and top of the nodes.
Fixes liquid sources and flowing surfaces having different brightness.
Fix mainmenu game initialisation
Fix the *CDP display
Add sqlite3 backend hack for android
Makefile support for build without leveldb
Remove temporary file at safeWriteToFile()
Fix inventory items blinking on item preloading
Revert "Fix inventory items blinking on item preloading"

The fix didn't work on some systems sadly this wasn't detected prior merge,
as preload is disabled by default now there's not gonna be a fix for it.
Let lighting be done only CPU side. Remove finalColorBlend implementation from shaders.
Make scrollbar scale according to DPI and scaling factor
Mod profiling support

Config settings:
profiling = true/false (gather statistics)
detailed_profiling = true/false (break mod times to callbacks)

Chat commands:
save_mod_profile saves current statistics in debug.txt and shows on console (on default loglevel)
Fix caption of config mods button (simple menu)
Don't call a player event without having player to do a event for
Pass light sources in blue channel of vertex color instead of decoded light for all special drawtypes.
Plus some style fixes and optimizations.
Remove buildable_to nodes without dropping item when replaced by a falling node
Fix wrong Icon name in minetest.desktop
Correct spelling mistakes in documentation