Remove :slamhound-skip from regrow-test

We call require directly in the body instead since it's a special case
for testing.
Add link to vim-slamhound in README

We can rewrite this section as "Editor Usage" if another slamhound
plugin is written, or when nrepl-discover is ready.
Update examples in README, mention PermGen space OOM condition

Closes #55
Add todo.org
Correct symlink to slamhound.el at root

Commit a92a54044e547c2dfcd1502012eecc16736f0fe1 states:

    Move slamhound.el to root; symlink it into payload.

However, the symlink created pointed to itself. This was presumably a
typo on the command line.
Release 1.5.0