OpenStack Swift Functional Tests for G4S

This commit has the following changes:
  * G4S no longer accepts URLs that end in /.  A HTTP code
of 400 is returned when a / at the end of the object
is detected.

  * Directories can be created as objects setting the
content-type to application/directory and content-length
to 0.

  * Functional tests have been adjusted to work with
G4S constraints

Change-Id: I31038a59699a8e3eeaba902db322218c6400093e
Signed-off-by: Luis Pabon <lpabon@redhat.com>
Reviewed-on: http://review.gluster.org/5246
Reviewed-by: Peter Portante <pportant@redhat.com>
Tested-by: Peter Portante <pportant@redhat.com>