Allows for the submission of new gists and gist edits on the server end.
If a gist id does not exist the form action is set to create a new gist, otherwise
it is set for editing the existing gist.
A utility function is added to compose the gist information that is passed to the
server in JSON format from the form.
There is a problem in rendering the signed in user's gist if that gist has multiple
embedded files.  It appears the parsed markdown does not pattern match correctly,
beginning pre tag is terminated with the last file's terminating pre tag.
There are also some errors in caching that need to be addressed.