- We use C++ as an example to show how this API can be used while still
  providing an idiomatic interface in the wrapped language of choice.
- No testing yet.

- Remove CredentialsFactory as it's unnecessary
- Effectively make Credentials a channel factory, allowing different credential types to create different channel types - this gives us a hook so that InsecureCredentials can at runtime instantiate a different kind of channel as required - giving us a way of generating an openssl free version of grpc++.
- Server credentials not touched yet, but they'll need to be updated.

- Changed the unsigned char * + size to NULL terminated strings which
  makes sense for the PEM format. I may change TSI later (but the impact
  will hopefully be much more limited).
- Added a way to pass multiple key/cert pairs to servers which is needed
  when hosting more than one domain.
- Removed the C++ SSL credentials tests as we are going to have an
  option to not specify the roots which will then be derived from the
  environment (well-known platform dependent locations and/or
  environment variable).
- Fixed the php build which is the only one added in the run_test.py.
  This change will certainly break node, python and ruby.

failure.
	Change on 2015/01/09 by yangg <yangg@google.com>
-------------
Created by MOE: http://code.google.com/p/moe-java
MOE_MIGRATED_REVID=83634736