Merge pull request #58 from rupnikj/master

minor api change: all save methods return fout instead of self. nodejs code, graph binary save/load
N-gram generation. Hashing changes: feature space columns now correspond to the hash. New hashing function for the hash trick (murmur3). Comprehensive testing for text featureSpace added.
Merge branch 'master' of https://github.com/qminer/qminer
Merge pull request #59 from lrei/master

N-gram generation and Hashing changes.
Reverted BigStringPool to DJB hash - change was accidental
Merge pull request #60 from lrei/master

Reverted BigStringPool to DJB hash - change was accidental
text ftr extractor can now keep hash table in memory. matching test added.
removed eval from ftrspace test
Merge pull request #62 from lrei/master

text ftr extractor can now keep hash table in memory.
Merge branch 'master' of github.com:qminer/qminer
windows build fix