virschematest: Add regex filtering for directory contents
virschematest: Add regex filtering for directory contents

In some cases we have directories with mixed XML files in the test
suite. Adding regex filtering will allow testing subsets of the XML
files against schema.

Signed-off-by: Peter Krempa <2cf5c04c61aa466e4a47bfedc747d17279c72ffc@redhat.com>
Reviewed-by: Michal Privoznik <83d82aaba2eed257f4814b0c239c260c4caaadf0@redhat.com>

jardasgit/libvirt,jardasgit/libvirt,jfehlig/libvirt,crobinso/libvirt,jfehlig/libvirt,jardasgit/libvirt,jfehlig/libvirt,libvirt/libvirt,crobinso/libvirt,libvirt/libvirt,jardasgit/libvirt,jfehlig/libvirt,nertpinx/libvirt,zippy2/libvirt,zippy2/libvirt,olafhering/libvirt,olafhering/libvirt,nertpinx/libvirt,zippy2/libvirt,libvirt/libvirt,libvirt/libvirt,jardasgit/libvirt,crobinso/libvirt,zippy2/libvirt,nertpinx/libvirt,crobinso/libvirt,nertpinx/libvirt,olafhering/libvirt,olafhering/libvirt,nertpinx/libvirt