Ported matchers from upstream

[clamburger]

Changes in detail:

• All of the matchers have been ported from the upstream library. (This includes the match functionality, but not the score or feedback functionality.)
• All of the tests for the matchers have also been ported, and are currently passing.
  • Existing tests that contained more than one assert have been split into multiple tests (for the most part). Tests make use of dataProviders where possible.
• The minimum PHP version was updated from 5.3 to 5.5.
  • As part of this, all instances of the traditional array syntax were converted to the short syntax, as they were being used inconsistently.
  • Fixed a few issues that prevented the library from working on PHP 5.5.
• Documentation has been added for a lot of the matcher classes, primarily where changes were made.
• Deleted ranked_frequency_lists.json as we're able to use frequency_lists.json instead.

I've tried to avoid making any major refactoring or opinionated changes at this point, primarily sticking with the style of code already present.

Please feel free to let me know if you have any feedback.

[mkopinsky]

This is awesome - I'm really glad to have a partner in this project. Aside from just the remaining matchers and tests that I didn't get to, there are also lots of improvements in this - data providers, ReflectionClass to test protected methods, syntax consistency, and so on.