Added config files for the i3 window manager
Added Xdefaults
Added Xmonad config
Updated preamble in i3 config file (since it's not the default config)
Added Zathura config file
Switched Emacs config license from GPLv3 to CC

GPL license doesn't make much sense for a config file. (The point is to "give
permission" to others to use, copy, and modify.)
Added CC license to i3 config files
Switched to CC license for tmux config
Cleaned up Vim config preamble and added CC license
Added preamble and license to X11 config
Switched from CC to GPL license in Vim config since its a script
Added preamble and license to Xmonad config
Revert "Switched Emacs config license from GPLv3 to CC"

Using GPL since emacs config is a script

This reverts commit 7d583cb93b97940055bdd779f0755233dc1eed21.