add fuzzy kmeans application
Merge pull request #123 from fegin/master

Naming conflict fixed
fix the comments
add spectral_clustering application
rm empty lines in the end of the spectral_clustering
Merge pull request #122 from MaggieQi/master

add fuzzy kmeans application
add distance measurement option for spectural clustering application
Merge pull request #124 from MaggieQi/master

add spectral_clustering application
Rename `set` to `parse` for flags.
A few minor changes to the optimizations.

Get rid of unused before/after arrays.
When forcing nodes, return a reference to the underlying array.
Update Black-Scholes benchmark to be slightly more realistic
(different maturity, rate and volatility values for each "stock")
Backout HasStrictTraits change.
Backout changes from pretty print branch.
add Alternating Least Squares on Implicit Feedback method
add streaming kmeans application
fix implicit feedback als
add pca
Merge pull request #127 from spartan-array/flag-names

Rename `set` to `parse` for flags.
Merge pull request #129 from spartan-array/update-optimizations

A few minor changes to the optimizations.
fix operator so it won't produce opposite result when we deal with distarray and expr
Merge pull request #133 from EasonLiao/fix_operator

fix operator