Added support for non-string values to love.graphics.print()
Changed love module to init all classes before anything else
Moved graphics_initDefaultFont functionality -> font_initEmbedded
Made `filename` argument optional in love.graphics.newFont()
Changed default font to be real lua object

The default font is now created as a real lua object and added to the
lua registry under the address of its struct pointer. The
love.graphics.getFont() function can now be used to retrieve the default
font.
Changed screen canvas to be real lua object

The screen canvas can now be accessed by using love.graphics.getCanvas()
when it is set.
Neatened l_graphics_setCanvas and _setFont()
Removed redundant graphics funcs and graphics.h
Added onLuaPanic() function to main.c