Add rust-packaging builders, dist builders for all channels, fix some bugs.
Add rust-packaging builders, dist builders for all channels,
fix some bugs.

edunham/rust-buildbot,rust-lang-deprecated/rust-buildbot,aidanhs/rust-buildbot,edunham/rust-buildbot,rust-lang-deprecated/rust-buildbot,rust-lang/rust-buildbot,rust-lang/rust-buildbot,rust-lang-deprecated/rust-buildbot,rust-lang/rust-buildbot,aidanhs/rust-buildbot,edunham/rust-buildbot,aidanhs/rust-buildbot