Initial version of post-receive hook (snippets, 60d726a)

This is a Bash script modelled on the example post-receive-email hook script
that comes with Git. This is a base version of the script that parses the
standard input and mines git for information appropriate to include in the
corresponding XML-RPC post to the weblog.

Rather than having two, scripts however, the plan is to roll the functionality
of this script and that of the commit-feed.rb script into a single Ruby
script which handles everything.

Signed-off-by: Greg Hurrell <greg@hurrell.net>\