Merge pull request #176 from osmlab/develop

new release, bugs and features
Merge pull request #177 from osmlab/develop

merging css tweak into master
Merge pull request #178 from osmlab/develop

hot fix to select challenge when picking it
do not abort with a 400 bad request when the challenge exists

Instead, we should be updating the challenge. to be implemented. for
now, return empty message.
making the tasks_available function cheaper
Merge branch 'develop'

* develop: (23 commits)
  re-add static components for now
  fix multi line string formatting
  stats api call now uses cheaper functions, server name in challenge finished email
  have client use the cheaper stats functions, removing deprecated functions, nicer approximate stats wording
  making the tasks_available function cheaper
  making the get_random_task call less expensive
  pep8ifying
  repairing the model so that we have a proper relationship between task and challenge (requires migration)
  Replacing BSD with Apache license, after getting all contributors to agree by email. Addresses #155
  adding update cascade to foreign keys
  do not abort with a 400 bad request when the challenge exists
  Fixing typo in function ChallengeComplete function
  fix challenge complete email logic, and notifying users when challenge / task cannot be found
  Removing Flask-Mail
  Attempting to handle nothing left to do
  this fixes #182
  add debug output to validator
  Using bower as per #91
  removing recursive from cte in availability query
  removing confusing notification
  ...
limiting the number of tasks returned in get_random_task
removing random requirement for 'random' task
disabling stats for now
disabling stats for now