Added enums to the parser.
2 big updates:
   1) added vector groups - chunks of the vectors of the same group should be homed to the same nodes
   2) added enums to the parser.
Merge branch 'master' of github.com:0xdata/h2o

Conflicts:
	src/main/java/water/fvec/NewChunk.java
small fixes to make compile/run tests after previous merge with master.
Merge branch 'master' of github.com:0xdata/h2o
Added some comments to vector groups/enums.