Make dotfiles super better

- Finished cleaning up .gitconfig. Split aliases into a separate file.
- Added list of globally installed ruby and python packages.
- Added tmux.conf

TODO

- Work on
muttrc, irbrc, pryrc, rdebugrc, rspec, ackrc, homebrew_profile.
- Document .gitconfig aliases.
- Clean up el file and zsh files.
Refactor rake task and create directories
Merged