* Add descriptors test

* Update descriptors tests

* Add public descriptors

* Add test_desriptors.proto to test script

* Update composer files

* Remove references to GPBType, update tests to be compatible with c

* Update for c extension compatibility

* Remove nested enums for descriptor, update tests

* Strip leading '.' from descriptor name

* Update tests with test for getClass, fix OneofDescriptor

* Add new files to Makefile.am