Re-implemented all development Rake tasks in Thor. Now actually tested.

Fixes:
* https://www.pivotaltracker.com/story/show/25484287 & https://github.com/pivotal/jasmine/issues/183
* https://www.pivotaltracker.com/story/show/25485401 & https://github.com/pivotal/jasmine/issues/189
* https://www.pivotaltracker.com/story/show/25485953 & https://github.com/pivotal/jasmine/issues/159

tasks/jasmine_dev.rb

@@ -0,0 +1,18 @@
+require 'thor'
+require 'json'
+require 'term/ansicolor'
+require 'tilt'
+require 'ostruct'
+
+$:.unshift(File.join(File.dirname(__FILE__), "jasmine_dev"))
+
+require "base"
+require "js_hint"
+require "build_distribution"
+require "build_github_pages"
+require "build_standalone_distribution"
+require "build_standalone_runner"
+require "count_specs"
+require "execute_specs"
+require "release"
+require "version"