Merge pull request #180 from bvssvni/master

Use `glyph_cache` from opengl_graphics
Fixed readability of get_new_state match statements
Fixed path qualifiers
Merge remote-tracking branch 'upstream/master'

Resolving conflict with recent PR, nothing significant
Merge pull request #181 from mitchmindtree/master

Fixed readability of widget::get_new_state matches
Upgrade to latest opengl_graphics