Add build directory.
Use exclude instead of changing severity.
Update PHP_CodeSniffer from 1.4.7 to 1.5.2. This fixes a rule inheritance bug.
Apply coding guidelines (with exceptions) to the tests directory.
Merge pull request #269 from bantu/code-sniffer-tests

Apply Code Sniffer to tests folder

* bantu/code-sniffer-tests:
  Apply coding guidelines (with exceptions) to the tests directory.
  Update PHP_CodeSniffer from 1.4.7 to 1.5.2. This fixes a rule inheritance bug.
  Use exclude instead of changing severity.
  Add build directory.