Push new release branch:
1. Make sure branches 'master' and 'release' are synced up locally
2. update src/demumble.cc with new version (with ".git"), then
       git commit -am 'mark this 1.0.0.git'
3. git checkout release; git merge master
4. fix version number in src/version.cc (it will likely conflict in the above)
5. commit, tag, push (don't forget to push --tags)
       git commit -am v1.0.0; git push origin release
       git tag v1.0.0; git push --tags
       # Push the 1.0.0.git change on master too:
       git checkout master; git push origin master
6. Add binaries to https://github.com/nico/demumble/releases
   Build them with `-DCMAKE_BUILD_TYPE=Release`, strip after building.