ISIS: added generating of Destination Trees to support TRILL multicast
forwarding
new example topology for testing multi-destination frames
TODO: fixed distribution-tree generating
      speeded-up lsp redistribution on broadcast links
	  temporarily changed #define values for easier debugging
TRILL: added encapsulation of native multi-destination frames
..
Merge branch 'newinet' of https://github.com/kvetak/ANSA.git into newinet