* Add flatbuffer_cc library support

* Update flags so all the tests pass

Tests now all pass!

* Modify the tests to use the generated code

This should be a simple serialize/deserialize test of the new generated
code to make sure the bazel rules are doing something sane.

* Use generated monster_test.fb in testing/test.cpp

cmake drops it's generated code in tests/monster_test_generated.h
Instead of checking that in, let's generate it with bazel.

* Make grpc tests depend on monster_test_generated.h

* Remove redundant cmake dependency

This should address @aardappel's feedback.

* Run flatc for Android as well

This will fix the last travis.ci failure

* Add generated output folder and fix flags

* Move flatbuffers_header_build_rules to the library that uses it

* Use --cpp-ptr-type to fix android

Android was the only target using the STL emulation layer.  It needed
the --cpp-ptr-type flatbuffers::unique_ptr flag to work.  Add it!

* Roll back changes to use autogenerated monster_test_generated.

Flip tests/test.cpp to use the autogenerated file as well.