/usr/local/bin in the PATH

It's already in the PATH (added in /etc/paths) but it's the last search path.
That is no good for us using homebrew.
Using chruby and adding GNU coreutils to manpath
Some changes to the vimrc

Main ones:

* foldmethod is 'expr', and the expression folds long sh/python/ruby-like
  comments
* better collors for the fold and for search
* python indentation at 4 spaces
* scala support