Fixed behavior for SUSE OS grains in 2016.3

[meaksh]

What does this PR do?

This PR brings changes discussed in #33903 to 2016.3 branch.

Also includes other fixes in order to fix the behavior of OS-related grains for the different SUSE versions:

• openSUSE Leap: grains['osfullname'] = "Leap"
• openSUSE Tumbleweed: grains['osfullname'] = "Tumbleweed"

Unit tests are included in order to check OS grains for the different SUSE versions.

These new changes expect to be also promoted to develop branch if it's possible.

Tests written?

Yes

/cc @isbm

[cachedout]

I've read the case in the other PR for this and I agree, yet I really don't like putting core grains changes into point releases at all. I would vastly prefer that we limit this change to the develop branch.

I'm going to cc: @thatch45 on this one because I think we need to all agree on this before we do it. Thanks for your understanding, @isbm and @meaksh

[isbm]

@cachedout problem is that if someone is using your release, it won't work correct with the SUSE family and you will have complaints in the Issues section. And we have to fix it, because in our eyes it is a major bug while we are running many products on top of 2015.8 (still). However, if we keep this fix only to ourselves, then we will have a diverged packages: one is yours, a bad one, because buggy; and another is ours, also bad one, since it is different than the upstream.

In order to have it in a sync, this is the reason why we upstream this. Enterprise supported is always lagging behind the greatest-and-finest for a number of reasons... 😉

[thatch45]

@cachedout since this does introduce convergence on the SUSE platform between SUSE packages and our upstream I think that it does make sense to merge it in. The changes are also isolated to SUSE detection, so again, I think that this should be safe to merge.

[meaksh]

Thank you for the comments and clarifications :-)