Move utf8range into separate file.

Move utf8range into separate file. This is to make button.h and label.h
independent of font_rendering.h and thus independent of the lib free
type headers. This way layout headers can be included without pulling in
a dependency to lib free type.

But: None
Test: N/A
Change-Id: Ib2260c20755b0a396a568e25390b4923815b621e
4 files changed