Squashed 'src/machinetalk/proto/' changes from ed880a4..1bc94d5

1bc94d5 machinetalk-protobuf: fixed enum aliasing
d9549de machintalk-protobuf: added messages for EMC command

git-subtree-dir: src/machinetalk/proto
git-subtree-split: 1bc94d5a26d967900b1ccd3420d13659079fa279
Merge commit '4c0436145abcd9ca69b76c2bee5a861db15b5ff5' into machinetalk-preview-strahlex