Use Tern jump-to-definition search for quickeditt

Current changes:
 - Use tern's jump-to-definition search for QuickEdit.
 - Change jump-to-definition to just select function name and place cursor at the end of the name to match what other editors do.

Future plans:
 - support finding var definitions in QuickEdit.
 - don't fall back to old QuickEdit search when tern knows a symbol is a builtin.
 - get tern to provide whole function extent, including function body and JSDoc style comments, if possible.

Note that the futures depend on improvements in tern.