BZ1003211

This pull request replaces the old BZ1003211 patch and fixes an issue with the AlertHistoryView, as well as replaces the original acknowledged filter with the one from BZ1050686, and changing the REST-interface to have three separate parameters.

In short:

* Adds automatic recovery information to the alerts if there's a recovery alert fired.
    * Adds this information to the UI, showing which alerts have recovered and when.
    * Fixes also BZ1030667
* Adds support for filters in the Recent Alerts views and portlet.
* Three available filters for UI (RecentAlerts portlet and AlertHistoryView)
   * Don't show acknowledged alerts
   * Don't show alerts that are just recovering existing alerts
   * Don't show recovered alerts
* Filters are also available in the REST-API.