Remove branch functionality

The branch functionality is already replaced with rugged inside GitLab

See merge request !52

Remove rm-tag command

Not needed anymore because gitlab-org/gitlab-ce!3748 switched the functionality to rugged.

See merge request !54

Remove unused #list_remote_tags

This function is not used anymore inside GitLab.

See merge request !53

Prune during 'git gc' after all

See merge request !48

This reverts commit 1ca8a44f.

Never pruning loose objects at all is not really a solution for
anything, and it causes annoying `git gc --auto` warnings.

Add new command to list tags from a remote repo.

The output of the `git ls-remote` command is written to the STDOUT so
the client can read and parse the list of tags. If there is an error it's
also written to STDOUT.

Closes #39 

See merge request !47

The output of the `git ls-remote` command is written to the STDOUT so
the client can read and parse the list of tags. If there is an error it's
also written to STDOUT.

[ci skip]

Add the ability to fetch remote repo without tags.

When fetching remote repo with tags the new remote tags are mixed in
with the local tags (all tags are saved under refs/tags), this affects
the UI of the Project given that we're showing up tags of a remote repo.

REF: https://gitlab.com/gitlab-org/gitlab-ee/issues/116

See merge request !46

When fetching remote repo with tags the new remote tags are mixed in
with the local tags (all tags are saved under refs/tags), this affects
the UI of the Project given that we're showing up tags of a remote repo.

Use ssh key internal api to build the authorized-keys command on openssh 6.9

See merge request !42

This provides the integration point to the internal API to get the
ssh key from the internal API.

Add new required commands to update remote mirrors

Closes gitlab-org/gitlab-ee#116

See merge request !43

Fix git-annex issue when using SSH on a custom port

Easiest thing here is to use the full repo path on the server side.

Fixes https://gitlab.com/gitlab-org/gitlab-ee/issues/166

See merge request !45

Do not prune objects during 'git gc'

This is a workaround to reduce the impact of
https://gitlab.com/gitlab-org/gitlab-ce/issues/13524 .

See merge request !44

This is a workaround to reduce the impact of
https://gitlab.com/gitlab-org/gitlab-ce/issues/13524 .

[ci skip]

Added an optional --force parameter for gitlab-projects fetch-remote

The optional parameter will decide wheter to fetch using --force or not.
fetching with --force is a requirement for Gitlab Geo (https://gitlab.com/gitlab-org/gitlab-ee/issues/76) secondary node
replication.

This is a dependency for https://gitlab.com/gitlab-org/gitlab-ee/merge_requests/179

See merge request !41