Merge pull request #45 from zytron/master

Added ability to search for functions that return-by-reference
Make reference-returning global functions supported too in JumpToLocation

Tests added to these scenarios
Fix various function matching patterns for '&' reference returns

Special thanks for @zytron who made me realize that i forgot these
Normalize and check the return value of GetFunctionLocation()

The previous 0 (number) return value could match with any string value
also there's no point searching for docblock in a not found file