Remove mailcatcher

The mailcatcher gem does not work correctly when executed through Bundler.
Merge pull request #2685 from delynn/patch-2

Remove mailcatcher from bundler plugin
initial setup a la http://www.intridea.com/blog/2011/5/18/its-not-enough-to-bash-in-heads-youve-got-to-bash-in-minds-with-zsh#editinstallsh
modify behaviour for update to overwrite local change with remote origin/master
the proposed workflow means to manually push the changes to the repo and then sync them on all machines via update.sh
aliases for hgrep, pgrep, rgrep and global alias lafi (last file)
alias: ipython tunnel on ostwald
beautify output from alias ip_ostwald_fwd