Remove Trigger selection from Event Editor UI

Each component now has a single trigger. This single trigger will
receive different data based on what is clicked (to be implemented).
Add data attribute to Trigger, hook up to USMap.
Cleanup.
Change display name from Triggering Widget to Trigger as specified in #226.
Add state information from bound data sets to Trigger data.
Fix merge conflicts.
Templating.
TODOs.
Using text block as a pseudo-tooltip works.
Resolve merge conflicts.
Resolve merge conflicts.
Clean up warnings
Add z-index buttons
Add visibility binding, add z-index to all widgets

-Adds the ability to have hidden properties that are manipulated by
some other means (in this case, the z NumberProperty that gets its
values changed by the two ButtonProperty properties). Necessary for
HistoryMonitor to catch the change.
Re-add missing templates

No idea why, but these two templates were removed…
Fix botched merge.
Check for defined properties.
Fix edit event bug.
Check templates are not undefined.
Get rid of unnecessary getState