SFTP: stat cache updates
Merge pull request #341 from bantu/sftp-changes-20140510

SFTP: Rudimentary tests for file_exists(), is_file(), is_dir().

* bantu/sftp-changes-20140510:
  SFTP: Rudimentary tests for file_exists(), is_file(), is_dir().
Merge pull request #342 from terrafrost/sftp-statcache-changes

SFTP: stat cache updates

* terrafrost/sftp-statcache-changes:
  SFTP: stat cache updates
SFTP: add more unit tests
SFTP Functional tests: Keep story linear.
SFTP Functional tests: Make use of assertNotSame