Use client-sessions to securely store session data in cookies.

It seems client-sessions wants the cookie name to be the same as the name
of the property attached to `request` which contains the session data, so
I had to change the cookie name from `csol_state` to `session`. Hopefully
this isn't a big deal.
Fixing error codes, improving logging.
Renaming helper function to respondWithForbidden.
Fixing `testHandler` weirdness
Whitespace
Don't need this logging
Sigh. Filtering the activities.
Fixing typos and bad labelling

One of these days I'll learn how to write software :(
Ignoring 'errors' when email is just disabled
added similar badges to /mybadges page. fixes #595
added real similar badge data to myapplications page. on myapplications and mybadges detail pages, "similar badges" section will only show if there is similar badge data
removed mentors section from faq. fixes #557
removed truncation of description. fixed image link.
Merge pull request #614 from curlee/master

fixes for related badges
Merge pull request #612 from mgballard/master

Cleanup! And mobile visual adjustments.
Merge pull request #603 from christensenep/128-badge-issue-email-fixes

Improve logging and error responses in badge issuing webhooks
removing openbadger hooks as it's definied elsewhere now. merge conflict
corrected typo and modified copy as per meeting input
re-adding badge description truncation. this should stay in place until css truncation is in place. fixes #618
Merge pull request #620 from curlee/master

copy update. also re-adding truncation to badge desc