Bash: Add the code function

The code function shows information about all known runnable items.
Bash: Add generic alias to edit local bash config
Bash: Optimise ansi_color function

By not defining all colours variables when they won't be used.
Bash: Increase in-memory and on-disk history sizes
Tmux: Open split panes on current pane directory

This was the default bahaviour before Tmux 1.9, and I found it very
convenient.
Vim: Use the new Vundle command: Plugin

The Bundle command is being deprecated by Vundle, Plugin is the new
command. Use it.

Additionally, update some custom renames for Vim plugins.
Vim: Do not wrap around when doing searches
Vim: Re-enable arrow keys

I have already trained my fingers to use hjkl but having arrows disabled
becomes a source of annoyance when someone else is using my machine.