Click tailoring, xccdf or sds file to open in workbench

[mpreisler]

This is a tracker bug, we need:

• mime types for XCCDF 1.1, XCCDF 1.2, OVAL, SDS, ARF, XCCDF 1.1 tailoring and XCCDF 1.2 tailoring in the mime database, we need a decision if we want those in openscap-utils or just scap-workbench
• set scap-workbench to open XCCDF, SDS and Tailoring files by default after installation
• when saving files we need to enforce .xml extension for good standards, otherwise mime type detection won't work
• (nice to have) mime type for scap-as-rpm RPM and bzipped variants of XCCDF, OVAL, SDS, ARF and tailoring files.

Original trac ticket: https://fedorahosted.org/scap-workbench/ticket/244

[mpreisler]

This would be really nice to have but I am postponing it to the next release. It needs changes in openscap that I can't deliver for 1.1.0 release.