.zshrc: New functions and added ctrl+R for search

* "cdls" now uses ; instead of && between cd and ls.
* New yank and put functions added. Yank <file> writes its path to
  a file called ~/.clipboard, and put cp's that file to the current
  directory. So basically enables copy+paste between terminal windows.
* Figured out that bindkey -v breaks ctrl+R for search and how to fix it.
.vimrc: Make :%s have g default; add colorscheme
Add symfony_modified Vim colorscheme
rc.lua: Use xterm and make other minor tweaks

The other tweaks are: changed tag names back to "1 2 3 4" to save
space, and commented out the mute keybinding until I feel like
fixing it.