update guava version from 11.0.1 to 14.0.1
make binSearch a tail-recursive method
Fix occasional failure in UI listener.

If a task fails before the metrics are initialized, it remains possible
that the metrics field will be `None`. This patch accounts for that possbility
by keeping metrics as an `Option` at all times.
Merge remote-tracking branch 'pwendell/ui-updates'
fix formatting and use Vector instead of List to maintain order
Merge pull request #668 from shimingfei/guava-14.0.1

update guava version from 11.0.1 to 14.0.1
update to use ListBuffer, faster than Vector for append operations
Merge pull request #679 from ryanlecompte/master

Make binSearch method tail-recursive for RidgeRegression
renamed with labeled prefix
Merge pull request #687 from atalwalkar/master

Added "Labeled" to util functions for labeled data