refs #3332: more cross browser compatibility and other fixes

 * the popover location is not put after a second hash anymore because that caused trouble in safari and internet explorer. instead, a popover parameter is introduced.
 * special url encoding for the popover location to make sure it's en- and decoded the same number of times.
 * minimum width for the label column in tables with row action.
 * tooltip behaves slightly nicer in ie7.
 * fixing a regression that broke transitions for subtables in the page titles report.

 * now transitions works in ie789, safari, firefox and chrome. in ie78, the css3 properties of the center box (border radius and shadow) don't work and excanvas can still be pretty slow sometimes. apart from that, everything's fine.
 * tested for memory leaks in all browsers. none found.

Apart from translation and documentation, that's it!

PLEASE TEST AS MUCH AS YOU CAN AFTER THIS COMMIT!

git-svn-id: http://dev.piwik.org/svn/trunk@7133 59fd770c-687e-43c8-a1e3-f5a4ff64c105