first pass at mailhooks, draft
got image emailing in working mostly
lots of fixes, true file names make it thru, expiiration stuff, etc
got check for new free responses working with timestamps
changed away from timestamps for checking for new free responses
switched to button look for answer adding, made refresh button better
fixed some bugs
removed debugger
cleanup
Merge remote-tracking branch 'origin/master' into jpslav-mailhook

Conflicts:
	Gemfile
	app/models/student_exercise.rb
	app/uploaders/free_response_uploader.rb
	app/views/student_exercises/_add_and_turn_in_free_responses.html.erb
	db/schema.rb
bumped babbler to more PC version
got rid of bogus text
killed OBE line
now only rescuing StandardError
fixed which links were limited to admins also made all available in dev; fixed kim's bug where emailed in photos weren't auto refreshed when no other free responses were already on page
fixed other exception rescue stuff
Merge remote-tracking branch 'origin/master' into jpslav-mailhook

Conflicts:
	Gemfile
fixed caption for emailed images
now uploaded images are oriented correctly if that info is present in the image, like from an iphone
Merge pull request #236 from lml/jpslav-mailhook

Let students email in files