ShifuML/shifu — pull request #18 by lisahua (2014-07-08 22:42:22+00:00)
Title: Revert akka version back to 2.1.1, exclude akka in plugin-spark

1. Revert akka version in Shifu-core back to 2.1.1
2. shifu - pom.xml: add plugin modules: shifu-plugin-spark,
shifu-plugin-mahout
3. shifu-core:
a) add ml.shifu.core.plugin.pmml package for the plugin interfaces.
b) add ml.shifu.core.plugin.pmml.PMMLModelTest which is the abstract
test cases for all pmml model test cases.
4. shifu-plugin-*: update pom.xml and separate dependency