Added report that shows full and parametrized activity log

Examples of reports:
 * /report/activity - all commits (default metric) in default project_type and
   default release
 * /report/activity?metric=marks&module=glance - all marks in Glance
 * /report/activity?metric=commits&module=glance&user_id=vsergeyev&release=icehouse -
   all commits into Glance from specified user during Icehouse
 * /report/activity?metric=commits&project_type=all&release=all&query_message=docimpact -
   all commits into all projects and all releases that have 'docimpact' in message

Change-Id: I51a3981429a3eafa320199244e4c06796cea4b19