Merge pull request #231 from ccri/develop

Distributed Representations of Sentences and Documents
auto-prune Dictionary for extra large feature space
* default limit = max 2 million features, but adjustable via param
update install instructions for py>=2.6
add Tim to CHANGELOG for doc2vec
improve logging in Dictionary
Corpora slicing

- Corpora now implement slicing syntax. For example, corpus[::2] gives
  you even documents
- Re-serialize corpora to generate matching .index files
- Make IndexedCorpus return a SlicedCorpus (generator)
Merge pull request #246 from piskvorky/corpora_slicing

Corpora slicing
Distributed LDA/LSI Python3 compatibility

Fixed import of the queue/Queue module to be compatible with
both Python2 and Python3
Merge pull request #249 from bonzanini/distributed-py3

Distributed LDA/LSI Python3 compatibility
update version of dependencies
Merge branch 'develop' of github.com:piskvorky/gensim into develop
Merge remote-tracking branch 'upstream/develop' into develop