Update MomentTensorPage and SummaryDetailsPage destroy methods.
Update tests.
Set this._toggleButton to null in ininitialize.
Change this._toggle to this._toggleInfo, no need for separate property.
Use this._toggleButton reference in destroy method.
Update destroy to remove click bindings from each summary section.
Fix bug on page caching.
Merge branch 'destroy' of https://github.com/ehunter-usgs/earthquake-eventpages into ehunter-usgs-destroy
Use a line merge threshold proportional to beachball size. Fixes issue #35.