Summary: Add type-checking/lookup routines for method references
Reviewed-by: jjg, dlsmith

Summary: Add class to handle inference variables instantiation and associated info
Reviewed-by: jjg, dlsmith

Summary: Make error messages generated during Check.checkType more uniform and more scalable
Reviewed-by: jjg, dlsmith

Summary: method applicability check should fail if formal varargs element type is not accessible
Reviewed-by: jjg

Summary: Resolve.java should keep track of all candidates found during a method resolution sweep to generate more meaningful diagnostics
Reviewed-by: jjg

Reviewed-by: darcy

Summary: Added global sanity check in order to make sure that return type inference does not violate bounds constraints
Reviewed-by: jjg