Rebasing of work branches allowed?

[Friedrich W. H. Kossebau]

Hi,

in other projects I have got used to the habit that, when updating a work 
branch to the lastest changes in the master branch, to rather rebase the work 
branch to the master branch instead of merging the commits from it, to keep a 
clean history in the branch itself, which I have found useful.

Is this approach allowed/supported for the Calligra repo? I would then do that 
with "my" filters-karbon-cdr branch.

On other notes:
I accidentally pushed an old branch "CDRImport" to the official repo. But it 
seems I cannot remove it again? Could someone with the proper super-powers 
please help out?

Cheers
Friedrich