Ogr

- ogr now correctly raises `OgrException` when given invalid URL to
`PagureService.get_project_from_url`. (705)
- We have fixed a bug in ogr that caused `IssueTrackerDisabled` being raised
only when trying to create an issue on git project with disabled issue
tracker. Now it is also raised when getting a specific issue or
an issue list. (703)

- We have added a new optional parameter, `namespace`, to the `fork_create` method on Git projects, which allows you to
fork a project into a specific namespace. (Forking to namespaces is not allowed on Pagure.) (685)
- We have implemented a `get_contributors` function that can be used to get the contributors of a GitHub
(set of logins) and GitLab (set of authors) project. (692)
- We have introduced a new exception class `GitForgeInternalError` that indicates a failure that happened within the forge
(indicated via 50x status code). `\*APIException` have been given a new superclass `APIException` that provides status
code from forge (in case of error, invalid operation, etc.). (690)
- We have added a new property to git projects, `has_issues`, that indicates whether project has enabled issues or not.
Following up on the property, `create_issue` now raises `IssueTrackerDisabled` when the project doesn't have issues
enabled. (684)

- `Release` class has been reworked and `create_release` has been made part of the API for `GitProject`. (670)
- Factory method for acquiring project or service class from URL has been improved by checking just the hostname for determining the service. (682)

- We have added `target_branch_head_commit` property to the `PullRequest`
class in `ogr` that allows you to get commit hash of the HEAD of the
target branch (i.e. base, where the changes are merged to).

- We have introduced a new function into `ogr` that allows you to get commit
SHA of the HEAD of the branch. (668)
- A list of Gitlab projects provided by `GitlabService.list_projects()` now
contains objects with additional metadata. (667)

- OGR now fully supports getting PR comments by its ID.