Identify structure of GitLab URLs for listed scenarios

[ehuelsmann]

We need to understand the GitLab? URL structure for the following scenarios:

1. A listing of (all) available projects
2. Browsing HEAD of the default branch
3. Browsing HEAD of a named branch
4. Browsing a specific commit as a uni-diff (full commit)
5. Browsing a specific commit as a uni-diff (single file within commit)
6. Browsing the 2nd to 4th item with blamed content
7. Browsing the 2nd to 4th item with raw content

[ehuelsmann]

Scenario	URL structure
1. Listing of projects	​https://gitlab-test.common-lisp.net/explore/projects
2. Browsing head of default branch	<unknown without knowing the default branch>
3. Browsing head of named branch or commit	​https://gitlab-test.common-lisp.net/<group>/<project>/tree/<branch-or-hash>/<within-repo-path>
4. Browsing a specific commit as uni-diff (full commit)	​https://gitlab-test.common-lisp.net/<group>/<project>/commit/<commit-hash>
5. Browsing a specific commit as uni-diff (single file within)	<not supported>
6. Browsing blamed content	​https://gitlab-test.common-lisp.net/<group>/<project>/blame/<branch-or-hash>/<within-repo-path>
7. Browsing raw content	​https://gitlab-test.common-lisp.net/<group>/<project>/raw/<branch-or-hash>/<within-repo-path>
8. Browsing highlighted file content	​https://gitlab-test.common-lisp.net/<group>/<project>/blob/<branch-or-hash>/<within-repo-path>

[ehuelsmann]

More URL structure:

9. URL for logs	​https://gitlab-test.common-lisp.net/<group>/<project>/commits/<branch-or-hash>
10. URL for raw unidiff	​https://gitlab-test.common-lisp.net/<project>/<project>/commits/<hash>.diff

[ehuelsmann]

Structure has been identified "enough" to be able to implement sufficient rewrites.