More robust full upload (at least regarding files changed to dirs and vice-versa).
* tests/test_upload.py:
(TestUploadMixin.transform_file_into_dir): Work around bzrlib
limitation by doing a remove/add when a file is changed into a
dir (we may reconsider when bug #205636 is fixed ;-).
(TestUploadMixin.test_change_file_into_dir,
TestUploadMixin.test_change_dir_into_file): Moved from
TestIncrementalUpload since full upload can now handle the cases.
* __init__.py:
(cmd_upload.upload_file_robustly,
cmd_upload.make_remote_dir_robustly): New methods.
(cmd_upload.upload_full_tree): Use more robust methods.