use murmurhash
merge from master
Merge branch 'master' into recommend-mh
murmurhash used + testcases
-O3
Merge branch 'master' of https://github.com/JohnLangford/vowpal_wabbit into recommend-mh
catch up with master
Merge branch 'master' of https://github.com/JohnLangford/vowpal_wabbit into recommend-mh
removed recommend testcases
update refs for test 27
update ref for test 28
refs for tests 30 and 31: feature mask
ignore *.prev files
Merge pull request #189 from petricek/recommend-mh

recommend.cc uses murmurhash