make return type more precise
more support for Java 7:
  analysis now understands and propagates MethodHandle objects
  fixes to Shrike InvokeDynamic instruction


Former-commit-id: fb826f124423bcbca08f729cee1794fbda711d16
remove debugging file


Former-commit-id: a4284ca571047d1e5e02fa5d142680a59993fe54