added deterministic vectors

Added option for deterministic initial vectors

Gensim already had the ability to precisely reproduce a model by using the
same seed when training on the exact same corpus.  The array syn0[] will
always have the same vector at each index.  However, models trained on
separate corpora or even slightly different corpora may have
different vocabs in different orders.  I add an option to use
"deterministic" initial vectors to link the seeding for the creation of
each vector directly to the corresponding word via hashing.  I also
concatenate onto the word the seed specified in the arguments so that a
user can tinker with different deterministic initial vectors with
reproducible results.
remove murmurhash3, substitute built in hash

avoids importing mmh3 module
Comments cleanup (minor edits)
restore altered spacing (minor edit)
Removed deterministic option-make default behavior
comment changes + forgot to remove parameter
added optional parameter hashfxn
removed unnecessary comments
Merge pull request #240 from KCzar/develop

Added Deterministic Vectors