Fix broken assertion in ParameterAssertionException

[thiemowmde]

This patch:

• Fix actual bug in ParameterAssertionException.
• Switch execution order in parameterElementType for performance reasons.
• Simplify odd $argname variable name. It's called $parameterName in the exceptions. In methods that already have parameter in the name $name should be enough.
• Add a comment to the strtolower call.
• Fix newlines at the beginning and end of all files.

[brightbyte]

Travis build fails on hhvm only due to an incompatibility between the latest versions of hhvm and PHPUnit.