Resolves php-weasel-23 Annontations aren't picked up if the class isn't in a namespace

Added test cases for the PhpParser.
Fixed bugs in PhpParser:
   * Fully qualified use statements were unusable. Suspect this was the actual problem originally reported.
   * Ignore comments and docblock comments.
   * Multiple use shorthand syntax support didn't work and led to none of the use statements  being picked up.
   * Fixed case where multiple namespace declarations appeared on the same line as the class declarations. This corner case probably wasn't really worth fixing, but nevermind.
Lob an InvalidArgumentException if we get asked to process something that isn't json.