Remove dependencies on internal headers from Java gRPC compiler plugin.

Instead, use functions from names.h which is going to be exported in the
opensource protobuf.

Also tailor includes to work with the current MOE configuration.
	Change on 2015/01/09 by zhangkun <zhangkun@google.com>
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Created by MOE: http://code.google.com/p/moe-java
MOE_MIGRATED_REVID=83619218