Handle interface names containing "."

[larsks]

This fixes https://bugzilla.redhat.com/show_bug.cgi?id=1057938 for
astapor by calling regsubst() to replace "." with "" in interface names
when looking up ipaddress* facts.

[cwolferh]

Nice!

[jguiditta]

Lars, thanks for the contribution, this has popped up in a couple variations recently. Apparently this is no longer able to be automatically merged. I can either fix it in my own checkout of your branch and merge it that way, or you can update, either way. Also, minor request, which I can do if you are busy (I really need to update the readme or add a contributing file). For BZs, it makes it easier on me to make sure I catch the relevant info in the spec changelog if people use the following format:

BZ #<number>, #<number> - short summary

<bz link(s)>

any additional text

I specifically call out plural in this case because I think your fix corrects 2 BZs, which has not happened to me before. The second is for rhos, here, if you care to include:

https://bugzilla.redhat.com/show_bug.cgi?id=1056892

[larsks]

I'll update the patch...should have it ready in a jiffy.

[larsks]

Updated patch is #111.