[2.0.0] - Implement functions for phpunit tests

2 first commits:
I have implemented all functions of \Phalcon\Paginator\Adapter\queryBuilder (and added comments - same as branch 1.x).

Now you can activate paginator test in phpunit.xml.

third commit:
Please do a big check for the third commit, I have rewrite the function \Phalcon\Http\request->getUploadedFiles(boolean)

Now all phpunit tests work (requestTest.php)

Fourth commit: Fix memcache set function call parameters
    before: memcache->set(lastKey, cachedContent, tt1);
    after: memcache->set(lastKey, cachedContent, 0, tt1);
php manual: http://php.net/manual/en/memcache.set.php