absorb Tamzen.rb into Rakefile
GH-2: drop blank glyphs from Powerline font patcher

These blank glyphs prevented other fonts from supplying real ones.

https://github.com/sunaku/tamzen-font/issues/2#issuecomment-51993873
bypass my openbox rules for the screenshot xterm
regen fonts with Powerline blank glyph clearing
GH-2: rebase changes from Tamsyn 1.10 (2013-09-14)