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.
Fix botched merge.
Check for defined properties.
Fix edit event bug.
Check templates are not undefined.
Fix merge conflicts
Merge
Remove pointer-events:none.
Remove old trigger references.
Rename triggeringComponent -> triggeringWidget in DependencyChecker