CStrChunk: String based chunk
Basic integration of CStrChunk

Conflicts:
	h2o-core/src/main/java/water/fvec/CStrChunk.java
	h2o-core/src/main/java/water/fvec/NewChunk.java
Merge branch 'cstrchunk' of https://github.com/avati/h2o-dev

Conflicts:
	h2o-core/src/main/java/water/fvec/NewChunk.java
Merge branch 'master' of github.com:0xdata/h2o2