Baseline for HT version of snippets

* change the name from fssnippets to ht-snippets

* update to work with python27 (mostly webapp -> webapp2, and minor
edits to app.yaml)

* modified scheduled tasks to nag on Friday at 3PM and send digest as
noon on Monday

* duplicate London timezone info for BST calculations (similar to
Kushal’s existing work for Eastern timezone)

* store & display the time snippets email was processed