Unify and improve run_command() implementations.
Check name should be unique (just like suite, component and arch)
Use column defaults instead of setting the default values in every constructor
Remove explicit JobDependencies association class

Also some streamlining of Binary/Result creation.
Some arch-only builds fail without the arch:all packages, so build the arch-indep packages first.
Add special "source" pseudo-arch.

Implicitly include both pseudo-arches ["source", "all"] where appropriate.
Support recursive debilization

Source/Binary/Job/Result is special-cased to avoid duplication and/or infinite recursion.
Add dsc and deb path info to the DB, Move files from Job to Result, Misc related cleanup.
Merge remote-tracking branch 'upstream/master' into upstream