Bash: Support Morgan Aldridge OS X tools directly

Instead of using an out-of-date copy of Morgan Aldridge's tools-osx
directory for things like our `trash` script, this commit allows us to
use a checkout of his tools-osx repo directory.

We first `rm` our out-of-date `trash` script from `./bin/trash`. Then,
in ./.bash_profile, we add a line which adds the 'src' directory of our
tools-osx checkout to the PATH.

While tools-osx nominally comes with an install script, this script
copies all of the scripts contained in that repo to /usr/local/bin.
I would rather not have these scripts installed into a global
directory,
especially not one managed by Homebrew, so it's easier to just add
their
location to the PATH (and to compile the one MacRuby script manually.)
Bash: change path to tools-osx; add diagnostic msg

We change the path of tools-osx from
'~/Documents/code/mac-scripts/tools-osx/src' to
'~/Documents/code/tools-osx/bin'. This keeps it out of our mac-scripts
directory, which is already linked in ~/. It also makes sure to add the
compiled bin directory, not the src directory.

Our ~/.bash_profile script will now display a message if it doesn't
find
tools-osx in the expected spot on terminal login. This is the only set
of tools .bash_profile will audibly complain about if missing, simply
because it's so useful, yet easy to forget to download and compile it
when installing a new system.
Vim: add indent guides plugin (\ig keymap)