Starting from 3.0.0 release, generated Java code will subclass
GeneratedMessageV3 and when we need to make a change to the
interface between generated code and GeneratedMessageV3, we
will create another versioned GeneratedMessageV3_1 and so on.
Change-Id: I178c9671beb78ef33901a133caaa5c765433126e
Moving the files to their original location, so that opensource changes
can be picked during the internal merge. Those files will be moved into
the correct location after merging with internal code.
Note: do NOT merge this into master without the other internal
down-integration commit.
protobuf/java will become a parent pom that will contain two modules:
core - contains all of the code for the protobuf-java artifact
util - contains all of the code for the protobuf-java-util artifact
Also cleaned up various Maven warnings.