sit,ipip,gre: generate tunnel configuration on tunnel change calls

bnc#901402
ifconfig: fixup tabs
Merge pull request #457 from kmroz/tunneling-cosmetics

ifconfig: fixup tabs
Merge pull request #456 from kmroz/bnc901402

sit,ipip,gre: generate tunnel configuration on tunnel change calls
compat: fix tap group node generation
Merge pull request #458 from pwieczorkiewicz/tap_group

compat: fix tap group node generation (bnc#904380)