Return the selected index from the selected event

	modified:   web/js/synmap.js
	modified:   web/tmpl/partials/synmap_results.tmpl
Sync transform Dropdown with selected dataset

The dataset sets updates the Dropdown to properly represent the current
transform applied to the data.

	modified:   web/js/synmap.js
	modified:   web/tmpl/partials/synmap_results.tmpl