Add Source Code Pro, fix some things for Debian.
Move .Xdefaults to .Xresources, since the former is apparently deprecated.
Add a few color and font tweaks.
Add vim-airline with fancy patched SCP font.
Add vim-fugitive for airline git integration.
Add vim-lawrencium for hg airline integration.
Fix zsh keys for xterm.

(The issues with font tracking in urxvt have driven me away from it;
in the past I had rolled back some particular lirary but it just keeps
breaking and looking awful.)
Make xterm's TERM report 256color.