Add support for custom queries and multiple runs.

Also, fix errors about fontface and media selectors
Modify results format to give more information

Now results have a rule list instead of both arrays in the past.
The rule object has the following format:

rule
  ruleSelector
  applied
  parts
    selector
    count

Add cssExplain for future plans
Rework statistics function to the new results format
Export result rules for further user exploring
Improve support for custom queries

Load Underscore as dependency to allow for easy extensions
Change custom partial function for the underscore one
Because of that, move the defaultStatistics initialization to the beginning of checkRules
Cange all new js functions (map/reduce) to use the underscore version for browser comp
Add a simple generic script loader
Improve dependency loader and fix missing paren
Set underscore minimun version on 1.4.4 (_.partial)
Change result format to make easier to calculate statistics