o Added entry about max-jobs which I forgot to include
    in the previous NEWS update

  o Added section for 1.3.2 and moved the recent additions
    to that new section

Backport junction element shorthand

See merge request BuildStream/buildstream!1502

In the previous commit, we added support to express cross-junction
dependencies inline as simple strings. Document it along with the
version in which the feature was added.

This doesnt match exactly the same way it happened in master,
so fixing it up in a separate commit.

This will allow cross-junction dependencies to be listed as strings on a
single line.

As part of this, some logic around initializing `Dependency()` objects
have been moved out of `_extract_depends_from_node()` method into the
constructor of `Dependency()` class, to keep all related code in one
place.

* _loader/types.py: While initializing `Dependency` objects, attempt to
                    split filenames, only if no `junction` was specified
                    explicitly. If a `junction` was specified, then
                    filenames with `:` in their names will result in an
                    error.

* _loader/loadelement.py: Refactor logic to initialize `Dependency()`
                          objects to move it to the `Dependency()`
                          constructor.

* tests/frontend/buildcheckout.py: Add tests to ensure the above.

* _versions.py: Bump BST_FORMAT_VERSION.

Fixes #809.

Backport build/runtime depends shorthand

See merge request BuildStream/buildstream!1501