Completed processing of blueprints data

 * Update blueprints with number of mentions (emails, commits, reviews)
 * Improved understandability of record processor tests (significantly refactored)
 * Extracted LP specific functions into launchpad_utils
 * Refactored activity template in UI

Implements bp metric-by-bugs-blueprints

Change-Id: I9008a84ef1960e54be6e61f0ef3d69cd2cc1d9e4