Qt metrics v1.2: Added timescale filter

Added Timescale filter with options "All" and "Since", the latter use
a calendar component to set the date. This affects both the Project and
Autotest dashboard in their level 1 view.

The calendar component taken from:
http://www.triconsole.com/php/calendar_datepicker.php (v3.69)

Tested with Chrome, Firefox, Opera, IE, Safari.
W3C validator gives some HTML5 errors/warnings on the calendar component
(author informed and correction requested).

Change-Id: If06f244dad60a3d251bf94664dce0e011060d829
Reviewed-by: Tony Sarajärvi <tony.sarajarvi@digia.com>