[Bugfix] Fix bug #792.

Details:
1. Fix bug #792. Elliptical zoom navigates to the wrong target.
2. Little math optimization in Elliptical Zoom.
Merge branch 'bug' of git://github.com/alex-zen/ChronoZoom into alex-zen-bug
Fix for bug with incorrect icon resize in tour stops
Bugfix for #843 - now user can delete timelines and exhibits without second warning dialog
Bugfix for #882 - Tour navigation closed when user clicked on edit icon
Bugfix for #800 - timeseries menu elements are now centered and look more neat
Merge pull request #950 from alterm4nn/bugfixes

Bugfixes - #800 & #882