Added button and code to call a rescale event on all sub measures.

Currently, the sub measure simply log their IPP.
Added and styled export button.

Supported toggling of scaling

Added update(data) method on the popChart to move the sections when it has
Fix issue where visual was attempted to be updated despite not having data.

Change arrow offset.
Moved scaling to a user preference to persist the selection
Changed to use more proper Thorax API instead of accessing "private" stuff.
Styling changes to the buttons for scaling.
Removed erroneous class from containing div
classes were being concatenated together, fixed that issue.
Checkboxes required names.
Fix issues with bootstrap popovers not appearing properly due to data not being populated prior to update being called.
Minor css change for readability

Used @$() instead of this.$()
Merge branch 'pop_chart'; fixes #205