Basic fileserver.

Returns index.html if it can't find the specified path
Also updated all the script/css paths to be absolute rather than relative,
since otherwise they'll spack out if index is served for a random route
Toggleable markdown rendering
More todos for gtwMarkdown directive
Semi working location based compareTo parameter.

It doesn't quite work correctly with the select box,
so I may be writing a directive for that later.
Factor out inital bit of the api request
Diff for the markdown text.

Next up is to port it over to the rendered html.
Rename gtwDiff to gtwTextDiff.

Directive rename will be in following commit.
Rename gtwDiff directive to gtwTextDiff
Pull third party libs out into vendor dir.