Add NERDTree and other minor tweaks.

vimrc: Add NERDTree and bind to <C-n> in normal mode. Enable line wrapping on mediawiki and taskpaper buffers. Change my mind again about CtrlP "working path mode".
Minor tweaks.

vimrc: Make NERDTree auto-close when opening a file; prefer DejaVu Sans Mono.
Add basic shell startup files.

environment: Defines environment variables.
functions: Defines shell functions.
shrc: Shell startup script; written for bash. Will pull in ~/.shrc.local if present for site local modifications.

startup: A unified startup script which loops through the above.

bashrc.sample:
profile.sample: Sample bashrc and profile that can be sourced or symlinked into place.
Merge branch 'master' of https://github.com/scrosland/dotfiles