Add more references.
Store the type of the symbol.
Support finding symbols using the type.
Merge branch 'references' of https://github.com/johnedmonds/codesearch into references

Conflicts:
	codesearch-index/src/main/java/com/pocketcookies/codesearch/CodeSearch.java
	codesearch-index/src/main/java/com/pocketcookies/codesearch/reference/visitor/CodeSearchReferenceVisitor.java