Introduce abstract class for functional tests.
Extract phpunit call to run-phpunit.sh
Add basic SSH2 functional test as an example.
Mark SSH2 Test as Incomplete on Travis PHP 5.3.3 and below for now.
Merge pull request #278 from bantu/functional-tests

Introduce functional tests (SSH2 as an example)

* bantu/functional-tests:
  Mark SSH2 Test as Incomplete on Travis PHP 5.3.3 and below for now.
  Add basic SSH2 functional test as an example.
  Extract phpunit call to run-phpunit.sh
  Introduce abstract class for functional tests.