update multinomial and chunking docs
update sampler for multinomial
update inference rule doc
throw exception when weight variable is null
change test heap size
Merge pull request #124 from HazyResearch/feiran-grounding_and_multinomial

New grounding and multinomial
Update test.sh
Merge pull request #126 from HazyResearch/develop

Develop
Add instruction about installing jekyll and reorganize structure a bit.
Edit and add links to changelog for 0.03.1

Rename changelog for 0.03.1 to correct name.
A lot of editing to the index, also containing the new structure of the docs.
Edits and grammar fixes.
Edits and grammar fixes.
New organization of the documentation
Fix links to documents following the new organization
Edits to inference/factor graph doc. Fix title of it in index.md
Some editing of 'general' documents
Assign a TODO to All
Editing of system overview
Editing of the installation guide.