Fixes #83 - EmberCPM.Macros.literal
Literal - address @stefanpenner's feedback
Merge branch 'master' into literal
Ember.literal - only allow string literals, in debug throw an error for any other type of argument
Ember.literal - don't rely on prototype extensions
Merge pull request #84 from TrueNorth/literal

Literal - to disambiguate between string literals and property keys in computed properties