Unbundle qtsingleapplication

[Johu-h]

Bundle libs have high risk for security issues. Its better to use a external version. See attached patch which unbundles qtsingleapplication.

See downstream bug for reference:
https://bugs.gentoo.org/show_bug.cgi?id=489146

[John Schember (user-none)]

Qt Solutions are not packaged by the vast majority of distros. It doesn't make sense to require a dependency that isn't available by must consumers of KDocker.

[Johu-h (johu-h)]

Depending on external lib would make distros, packaging it. For example it is already in Gentoo available.

[Johu-h (johu-h)]

Here is another patch which lets packager control wether internal qtsingleapplication is used or system one. This should work for distributions which are not able to package qtsingleapplication.

[John Schember (user-none)]

I'm fine with defaulting to the system install if present. Patch merged in revision 112.