Merge branch 'hotfix-schemachange' into develop

Avoid creating index on psql
Tutorial: label basic features, precision 4%
Added step1-basic code
Added BrainDump config for step1-basic
Fix bug in ddlib.
Add generic feature library
Merge branch 'develop' into release-mindreader
Support multiword keywords
Add Sen's homepage as per his request
Step2-generic features, precision 1%
Merge branch 'release-mindreader' of github.com:HazyResearch/deepdive into release-mindreader
Fixed a str-int concat bug in gen_feats.py

In python2, str and int cannot be concatenated using "+" operator, and
it will cause bugs if dict_id is not assigned. (use auto-incr ids)
Convert to str() whenever possible to avoid TypeErrors
More use of str()
Convert get_sentence to use the unpack_words method and add functions to convert from one format of the dependencies to the other.
Reorganize and add comments
add regularization parameters for sampler
Merge pull request #183 from HazyResearch/feiran-regularization

add regularization parameter
Merge branch 'release-mindreader' of github.com:HazyResearch/deepdive into release-mindreader
Add regularization parameter documentation