Better maintained jxrlib

[Albert Astals Cid]

Hello Distribution friends.

Some of you are shipping kimageformats with KIMAGEFORMATS_JXR enabled.

This requires jxrlib.

Sadly jxrlib is abandonware by Microsoft.

I would like to point you to https://github.com/mircomir/jxrlib

This is being updated by our own developer Mirco Miranda with patches to fix 
vulnerabilities found by oss-fuzz.

I would encourage you to adapt that if you are shipping jxrlib	.

Cheers,
  Albert