Fixed logic for PostMySQLDAO::doesUserHavePostsWithFaveLikes/RetweetSinceDate()
Handle return URLs to plugins with no hash

If a plugin is activated, the javascript will select that div
unless a hash is provided (such as #instances or #ttusers)

Closes #1780, closes #1782
Send Insight emails as HTML via Mandrill

Retains old behavior for ThinkUp installs without Mandrill configured.

Closes #1779, closes #1781

Handle missing template for mailHTMLViaMandrill

Explicitly catch Mandrill_Unknown_Template and rethrow when sending.
In InsightsGenerator email process, revert to non-templated mail in this case.
Throw other errors as was currently handled.
Add support in the isTest() mode to triggere exceptions.

Added Insights Generator Configuration to Docs