BM25, Co-occurrence Matrix, faster ROUGE, Fixing LSA.

[Ayushk4]

I am porting various implementations from StringAnalysis.jl and fixing various others.

• [X] Co-Occurrence Matrix

  • [X] Code
  • [X] Test
  • [X] Docstrings
  • [X] Documentation

• [X] BM25

  • [X] Code
  • [X] Test
  • [X] Docstrings
  • [X] Documentation

• [X] Speeding up Rouge.jl

• [X] Docstrings and Docs for Evaluation Metrics (Rouge)

• [X] Fixing lsa

• [X] Docs and tests for lsa

As per the discussions in #164 , I am preferring to port COOM from StringAnalysis.jl for various advantages discussed.

There seem to be performance bottlenecks in rouge.jl due to Abstract containers, this also needs to be worked upon.

[Ayushk4]

I have ported BM25 and Co-Occurrence Matrix from StringAnalysis.jl. Co-Occurrence Matrix works 10-15x faster than one in #164, uses less space, supports operations over Document and Corpus types.

LSA has been fixed. ROUGE - N has been re-implemented, supports languages, 15 - 20% improvement in speed and memory.

Tests, docstrings, online documentation added for all these.

@aviks, please review.

[aviks]

I've fixed merge conflicts, and added explicit license. attribution to zgornel in the coom.jl