Remove unused (and misplaced) hub alias
Remove unused RVM Bash completion

RVM long since abolished from here.
Ignore EOF to exit shell in Bash

At least, when done 10,000 times since Bash (unlike Zsh) does not allow
wholly disabling this.
Remove duplicated pman() definition
Make colors a function and make cross-shell
Handle ctags path globally, not per system
Handle no arguments given to play()
Remove no-longer used tower alias

Since replaced with tig.
Rename COLOR_NC to COLOR_NONE
Remove never-used snippets