Like Spike Insight
Closes #1722
View Spike Insight
Closes #1723
Subscriber Change Insight
Closes #1724
Minutes Viewed Insight
Closes #1727
Reply Spike Fixes
Closes #1732
Fixed Link Prompt insight error for no recent posts
re: issue #1620, closes #1731
Twitter plugin: Deactivate follows by 403 users

Added fix to class.TwitterCrawler.php and added a method to
class.TwitterAPIAccessorOAuth.php to return the numeric error code the
Twitter API returns.
Added additional test data to tests/ to for the new tests to consume.
Closes #1742, closes #1677
Gracefully handle links and links_short table 'Data too long for column' errors, closes #1529
[DB MIGRATION REQ'D] Add Daily and weekly insight email notifications

Adds notification_frequency setting to Owners,
adds to DAO, Model and Interface.
Adds ability to set frequency on account page.
Adds mandrill template option to InsightsGenerator plugin for future.
Sends email after insights generation if user is an admin.
Generates email and subject from smarty template.
Added tests for insights generator plugin controller.
Added tests for new owner features.
Added tests for crawl and email sending.
References #1589, closes #1770