RestrainedTextContainer: delete first content on rollover regardless of layout

and break out of the loop if we run out of layout
fix up EOF whitespace
SpriteRendering: just use the existing blit flags instead of defining new ones
GLDriver: clarify the coordinate assignments

this way should also be more optimized I think. most cases are without mirroring and even fewer cases have both.
also combine flags from the sprite with the flags param
FPS counter: add IE_FONT_SINGLE_LINE

fixes using inefficient rendering path.
Sprite: dont need or want this empty MakeUnused function
GLVideo: (partially) updating for blitter changes in 8fa1a97

this is largly untested beyond the menu, but there are obvious clipping issues on some things (TextAreas)