Stabilisation phase for 0.6.6 release

[Ferry Huberts]

OLSRd developers and users,

We have branched the development tree in preparation for the 0.6.6 release.
We're expecting a stabilsation period of about a month, depending on the
amount of feedback that we'lll receive.

The git branch is called release-0.6.6 and we invite everyone to test
olsrd from this branch.

The release-0.6.6 branch contains major fixes and improvements for the
smart-gateway system (multi-gateway!), and many other fixes.

Please test and let us know!