convert/bzr: handle empty bzr repositories (issue3233)

convert/bzr: convert all branches (issue3229) (BC) Instead of opening the target bzr checkout as a single branch, we try to open it as a repository. This has the following effects: - All branches are now converted - bzr branch names are preserved. Previously, the selected branch was always converted as 'default'. Branches without a name or 'trunk' are mapped to 'default branch. - Lightweight checkouts are no longer supported. Maybe they can be, I did not try to fix that at all. Implementation notes: - This was a quick fix, I have no knowledge of bzr API besides browsing 2.0.3 sources. - The fix was only tested on OSX against bzr 2.4.2. - Tags discovery does not handle collisions. I have no idea how tags work in bzr so maybe such collisions are not possible.

convert/bzr: expect unicode metadata, encode in UTF-8 (issue3232) Before this patch, metadata and file names were interpreted like: - unicode objects were converted to UTF-8 - non unicode objects were left unchanged Looking at the code and bzr being known for transcoding filenames, we expect everything to be returned as unicode objects, and we want to encode them in UTF-8, like the subversion source does. To do that, we just remove the custom implementation of .recode().

test-mq: fix sed call on OSX - The regular sed on OSX wants: -i "" not -i"" - GNU sed wants: -i"" not -i "" Backups are fine.

mq: rename secretcommit to newcommit This function create secret changeset only when mq.secret is true

merge with stable

i18n-de: update po and remove fuzzies

i18n-de: Rework and fixes continued

Added signature for changeset 2aa5b51f310f

Added tag 2.1 for changeset 2aa5b51f310f