Add UPnP renewal
Reannounce renewed UPnP mapping
Rediscover gateway on UPnP renewal
Restart port sequence when UPnP renewal fails
Set default UPnP renewal to 30 minutes
Update goleveldb
Mechanism to stop external announcement routine
Merge branch 'master' into pr/511

* master: (21 commits)
  Mechanism to stop external announcement routine
  Update goleveldb
  Perfstats are not supported on Windows
  Build should fail if a platform does not build
  Include perfstats and heap profiles in standard build
  Actually no, lets not do uploads at all from the build script.
  ./build.sh upload build server artifacts
  Sign checksums, not files.
  Badges, add build server
  Remove Solaris build again, for now
  Travis should build with 1.3 + tip
  Translation update
  Indicate aproximativeness of repo sizes...
  Slightly more conservative guess on file size
  Fix set tests
  Small goleveldb hack to reduce allocations somewhat
  Don't load block lists from db unless necessary
  Rip out the Suppressor (maybe to be reintroduced)
  Reduce allocations while hash scanning
  Add heap profiling support
  ...

Conflicts:
	discover/discover.go
Use new StopGlobal on the discovery when external port changes