We try to use default fallback for both mono and main font when custom font path is not exist. This way, if Minetest is not corrupted, we could avoid crash.
If you happen to have a font_path setting that is incorrect,
minetest will just attempt to start the gui without a valid
font which leads to a segfault later on.
We can attempt to load the fallback font path fairly easy,
but if that fails we should give up with a proper error message
and not a weird segfault later. This forces an abort() if
the fallback fails as well, and prints a useful error
message to the console.
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
