Fix and useful aliases

Added a fix for `updatepl` as at current it doesn't work. OX 10.9 bug see [here](https://github.com/davidcelis/powerline/commit/b988b1b8ac9ad7f355e634001565428f6b5bc0b1). 

Added an alias to checkout master branches without all the guff of `git checkout master` => `master`.

Added an export of $WORKSPACE which points to `$HOME/Code` and then an aliase of `p` that `cd`'s to that location.