Add 'Brainstem.Error' class
Update 'Brainstem.Utils.throwError' to use new error class
Fix Brainstem.Utils#throwError and add specs for it
Merge branch 'master' into fix_utils_throw_error

Conflicts:
	spec/brainstem-utils-spec.coffee
	vendor/assets/javascripts/brainstem/utils.coffee
Merge pull request #41 from mavenlink/fix_utils_throw_error

Fix Brainstem.Utils#throwError