Revert artifact/group name and version number.
Revert artifact/group name and version number.

Artifact/group name has been reverted back to
com.clearspring.analytics.stream. Version number
has been reverted back to 2.x series. Subtle package
management bugs were discovered when we tried to change
the artifact/group ids without changing the class package
names. If we change the package names we will need to handle
the serialization/deserialization logic to be backwards compatible
with old package names. Until these issues are resolved we are reverting
the names.

smartpcr/stream-lib,oertl/stream-lib,joychugh/stream-lib,smartpcr/stream-lib,joychugh/stream-lib,tempbottle/stream-lib,tempbottle/stream-lib,orneryhippo/stream-lib,oertl/stream-lib,orneryhippo/stream-lib