Fill Deep Learning tutorial with content (prostate classification).
Implement inflate_impl for C8D (double -> double), was called from RebalanceTask and failed.
Cosmetics
add ddply test to perf harness
fix data object logic boolean
Handle properly constant columns in DRF/GBM.

If a model is requested for train dataset containing
only constant columns, the request is rejected.

Fix of PUB-123
missing import h2o_exec
don't delete a key if it has '__Tree__' in it (deleting RF model deletes them)
do a remove_all_keys afterwards to clear out locked keys
Merge branch 'master' of github.com:0xdata/h2o
don't use RemoveAll.json
increase some timeouts when looking at the jobs list to 60 secs
c2/part_00000b dataset has always caused problems. Now it leaves it's parsed key locked, which causes stack traces when I try to remove etc (and I can't use RemoveAll reliably). taking part_00000b out of testing until it it works reliably.
Fixed formatting/printing bug in CXDChunk.
Revise DeepLearning tutorial docs and add references.
Merge branch 'master' of https://github.com/0xdata/h2o
fix typos
don't delete DRF_ model key maybe in flight?
Merge branch 'master' of github.com:0xdata/h2o
check if it's possible to exchange keys created by exec sessions on different nodes.
a little cleanup