Add ability to filter by a text query and highlight nodes

[bherr2]

Using Griffin's GetSearch endpoint and a graphical text filter, highlight matched concepts in the tree. Search for a concept like "asthma" and highlight the circles/boxes along the path(s) to the matching items. The endpoint is: http://HealthcareSystemDynamics.org/SumTreePCORI/GetSearch.asp?Strategy=Contains&MatchStr=Asthma

[bherr2]

First pass, highlights the labels up to the correct level. Second pass strokes the correct circles/boxes (the harder part).