Set the build status properly for failing local builds

If a build has ‘preferLocalBuilds = true’ (or we're not using remote building), and the build has a non-permanent failure, then the build status should be "Aborted" rather than "Failed". This is denoted by an exit status of 100 from nix-store.

Created by  Eelco Dolstra  on April 30, 2012
SIZ6KXPWOMMK44CPHSJ7NLLIWWDRWZNE3EPCN7NTF5VCRREXMU7AC
Change contents