Merge branch 'release-0.7.8'
Merge branch 'release-0.8.0rc1'
Merge branch 'release-0.8.0'
Merge branch 'release-0.8.1'
Merge branch 'release-0.8.2'
Merge branch 'release-0.8.3'
Merge branch 'release-0.8.4'
gitignore Vim temporaries
clean up and optimize Porter stemmer; roughly 20% faster

Ability to stem a substring of a string is gone; it took too much time.

Also cleaned up the comments, which were apparently copied verbatim from the
C version and referenced things like pointers and '\0'.
fixed underflow in HDP (reported by Greg Ver Steeg)
.gitignore extra dirs
Merge branch 'master' into develop
Merge remote-tracking branch 'larsmans/optimize-porter' into develop
improved lemmatizer docs
Proper XML parser for Wikipedia dumps
Split wikicorpus's __main__ to a separate script
moved `scripts` folder inside gensim
fix: doc string format
updated wiki docs for the new script path
moved simserver docs back to gensim
* simserver doesn't have its own build system for sphinx docs or hosting...