Beginning special casing for getOccurrencesAtPosition.
Implemented getOccsAtPos for try-catch-finally.
Made getOccs more resilient.
Added tests.
Support for switch/case/default/break in getOccs
Handled function boundaries.
Moved null-guards to appropriate places, added helpers.
Better coverage against function boundaries.
Replaced ES5 functions with analogous core.ts ones.
Made 'isAnyFunction' more exhaustive as it should be.
Addressed CR feedback.
What's in a name anyhow?
Removed assertion.
Merge pull request #549 from Microsoft/getOccurrences_switchCaseDefault

Get occurrences for switch/case/default/break keywords.