Implemented getOccurrences for for/for-in/while/do-while loops and their breaks/continues.

This includes labelled break/continue.
Changed logic for break/continue search in switch statements and loops.

Now if a labeled break in a switch refers to its original switch statement, we also highlight the 'switch' keyword.

Also added tests for loop/break/continue.
Merge pull request #639 from Microsoft/getOccurrencesConstructor

Implemented getOccurrences for 'constructor' keywords.
Extracted 'break'/'continue' aggregation into common helper function.

Also addressed other CR feedback. Still need tests.
Modified tests and added a test for labeled continues in a switch block.
Minor CR feedback addressed.
Simplified ownership code for continue/break statements.
Merge branch 'getOccurrences' into getOccurrencesLoopBreakContinue

Conflicts:
	src/services/services.ts
Merge branch 'master' into getOccurrencesLoopBreakContinue