Small improvement on clouds rendering performance

Move debug streams to log.cpp|h

Move GUI-related globals to clientlauncher

Move g_settings and g_settings_path to settings.cpp|h

Move g_menuclouds to clouds.cpp|h

Move g_profiler to profiler.cpp|h

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

Switch the license to be LGPLv2/later, with small parts still remaining as GPLv2/later, by agreement of major contributors

--HG--
rename : src/licensecomment.txt => licensecomment.txt