Start using expression language.
Add test.
Fix the ExpressionLanguage test.
* Remove ConstantParse
* Use Expression Language
Merge branch '7.x-2.x' into features/expression-language

* 7.x-2.x:
  Use codebase rather than making it
  Use codebase rather than making it
Using Expression Language: Fix warning.
Using Expression Language: Fix warning.
Merge pull request #59 from andytruong/features/expression-language

Start using expression language.