Various gui improvements for calciumdxevents.

* ~~change autoscale in dxevents~~ 2013-06-25 09:21:44
* ~~fix zoom in dxevents~~ 2013-06-25 10:27:27
* ~~fix cell nav for scroll vs number~~ 2013-06-25 09:07:34
* ~~add Same Y axis zoom toggle button~~ 2013-06-25 11:57:39
* ~~add option through menu to turn off zoom to use add events context
menu~~ 2013-06-25 11:58:53
* ~~add defaults for zoom and pan horizontal~~ 2013-06-25 11:58:48
* ~~link x axis for plots for consistent zoom and scroll behavior~~
2013-06-25 11:59:43