PIG-3461: Rewrite PartitionFilterOptimizer to make it work for all the cases (aniket486)

git-svn-id: https://svn.apache.org/repos/asf/pig/branches/branch-0.12@1525974 13f79535-47bb-0310-9956-ffa450edef68
PIG-3479: Fix BigInt, BigDec, Date serialization. Improve perf of PigNullableWritable deserilization

git-svn-id: https://svn.apache.org/repos/asf/pig/branches/branch-0.12@1526045 13f79535-47bb-0310-9956-ffa450edef68
PIG-3468: PIG-3123 breaks e2e test Jython_Diagnostics_2

git-svn-id: https://svn.apache.org/repos/asf/pig/branches/branch-0.12@1526050 13f79535-47bb-0310-9956-ffa450edef68
PIG-3360: Some intermittent negative e2e tests fail on hadoop 2

git-svn-id: https://svn.apache.org/repos/asf/pig/branches/branch-0.12@1526054 13f79535-47bb-0310-9956-ffa450edef68