[java] Fix class scopes for anon inner classes

[jsotuyod]

• A new ClassScope was being created for each annon inner class method / field,
  which is incorrect.
• I reworked the AccessorMethodGeneration to compare scopes directly, since
  I was missing anonymous classes completely.
• Fixes [java] AccessorMethodGeneration: Method inside static inner class incorrectly reported #274

[jsotuyod]

@adangel please check Travis, it's failing with:

The command "openssl aes-256-cbc -K $encrypted_5630fbebf057_key -iv $encrypted_5630fbebf057_iv -in .travis/secrets.tar.enc -out .travis/secrets.tar -d" failed and exited with 1 during .

[adangel]

I think, I've fixed the travis build. Didn't think about that secure vars are not available for pull requests.
Could you please rebase this PR against master and give it another try?

[jsotuyod]

@adangel thanks! I just rebased and it built just fine!