Fixed comments. Updated debug outputs.
Fixed indentation.
Set links up when probing interfaces during installation. See bnc#792985.

Setting interfaces up used to be side effect of NetHwDetection before.
However this side effect was removed when fixing bnc#782283.
Updated changelog.

NetHwDetection::Start() used to set up all links which was undesirable
outside the installation (bnc#782283) so we thought we made it
installation specific in commit 3b7a739 when the side effect was moved
into new function SetAllLinksUp and  called from Lan::Read()

But we did not notice that this side effect was needed by a different
caller, inst_netprobe.ycp (bnc#792985).

Now we call SetAllLinksUp in inst_netprobe where it is needed. In
Lan::Read it does not help so it is removed.
Merge pull request #49 from mchf/Code-11-SP3

bnc792985 - eth not set up during installation