Remove short options -c/-t

Remove short options for --commit and --tree from bub save.
These two are probably more suited for debugging/testing, so unless
someone has a proper usecase for them, remove the short-options.

Signed-off-by: Tim Riemenschneider <git@tim-riemenschneider.de>
Remove short options -c/-t/-b

Remove short options for --blobs, --commit and --tree from bub split.
These three are probably more suited for debugging/testing, so unless
someone has a proper usecase for them, remove the short-options.

Signed-off-by: Tim Riemenschneider <git@tim-riemenschneider.de>
Fix testcases

The testcases used the short-options, which were removed. Use long-options.

Signed-off-by: Tim Riemenschneider <git@tim-riemenschneider.de>