appdata: fix bugtracker link

See merge request !30

gitlab issues are used for bugtracking. bugzilla is no longer a
thing.

Escape markup in property values

Closes #8

See merge request !28

This fixes an issue where property values that contained markup characters
weren't displayed.

Fixes #8.

We no longer need to manually keep it in sync with the ci.

The functionality of these jobs exists in the normal
build job now and they are no longer needed.

citemplates@544836ee

commit 3c82a664 added
an idle handler to help process introspection requests
asynchronously.  It failed to clear the idle handler id
when the idle finished, however.

This commit fixes that.

introspection: Load introspection data asynchronously

See merge request !26

Some projects, like systemd, have truely gigantic introspection trees.

At the moment that makes d-feet lock up.

To address that problem, this commit changes d-feet to process the
incoming introspection data from an idle handler.

!26