[LIBCLOUD-639] Fix upload_object_via_stream so it works correctly
under Python 3.x if user manually passes an iterator to the method.

Closes #408

Signed-off-by: Tomaz Muraus <tomaz@apache.org>
Add a clarification about fill_size improvements.
[google compute] fix ex_disk_auto_delete for create_node()
Closes #412

Signed-off-by: Eric Johnson <erjohnso@google.com>
[google compute] Add DiskTypes resource to GCE driver
Closes #391
[google compute] Add TargetInstance resource to GCE driver
Closes #393

Signed-off-by: Eric Johnson <erjohnso@google.com>