PDIO-158 #comment update backend to return default params in getSetting
enable mahoutitembased auto tune.
fix other algos' js and template for auto tune switch and method param
PDIO-158 #comment add default values for autotune param
PDIO-158 #comment update mahout-knnitembased backend and algo info for auto tune
PDIO-158 #comment refactor common param setting
Merge branch 'master' of github.com:PredictionIO/PredictionIO