Indentation; Changing shells advice; Hostname

* Makefile advises on how to change one's shell
* jt alias reflects actual hostname
* Sort out Vim spaces/tabs/softtabs/shiftwidth
* HTML files default to two-space indentation
* Add command to toggle showing of some whitespace chars
* Add commands to remove trailing whitespace globally and indent globally
* Automatically trim trailing whitespace on saving certain filetypes
* Disable rope for now
Vim tabs; spell-checking; plugins

* Implement Firefox/Safari-style tab navigation shortcuts in Vim
* Spell-checking settings in Vim
* Try out hexHighlight
Vim plugins; Makefile; Completions; Organisation

* Use YouCompleteMe
* Add helpful info to Makefile
* Add pip completion for bash and zsh
* Updated $EDITOR to use which (so if later vim's installed it'll use it)
* npm completions are cross-shell; DRY
* Put shell-related config in /shell
Vim Plugins

* Use ColorV
* Use NERD_tree