Starting to stub out filter functions.
Got the 'needs signature' filter working
Sorting and filtering seems to be working OK. Need to write some specs
Getting closer
Spec for Need Signatures done. Spec for Have Answers started but not passing yet
Reimplemented the approach for question sorting. Still need the specs written
Most specs written for new questions controller stuff
Got the specs written for questions controller
fixed specs for question filters
hardened threshold_met? logic
Some code refactoring & code style tweaks

Closes #167 & closes #124
Merge remote-tracking branch 'upstream/master'