Fix functional tests

* The order of elements in list returned by listdir() can vary and may
  not be sorted. This caused assertEqual in "test_listdir" to fail.
* Also, some systems may have xattrs belonging to selinux. So, a
  listxattr can list them too.
* Allow hostname/ip and volume name to be configured easily by setting
  it in test.conf. This enables functional tests to use a non-local volume.
* Cleanup volume before and after running functional tests.
* Added MANIFEST.in and LICENSE file

Change-Id: Icfa6eb60e8d8e7ed4d6ab8190a2a2c80688999a3
Signed-off-by: Prashanth Pai <ppai@redhat.com>