tmux: Prefix is Ctrl+a.
xmonad: Terminal is gnome-terminal.

st is kind of primitive, although I haven't checked out options.
env: Editor is vim.
vim: C indent 8 space hard tabs.
alias: Clean up alias file.
alias: Add tmux aliases.
layout: Move non-dot-files to etc/.

--HG--
rename : Gemfile => etc/Gemfile
rename : alias => etc/alias
rename : crontab => etc/crontab
rename : env => etc/env
rename : offlineimap.py => etc/offlineimap.py
rename : prompt => etc/prompt
rename : python-packages.txt => etc/python-packages.txt
rename : software-list.txt => etc/software-list.txt
rename : xstartscript.sh => etc/xstartscript.sh
i3: Remove it from tree.
scripts: Cleanup.