Bug#720458: autopkgtest: allow tests to depend on Build-Depends installed

[ansgar@debian.org (Ansgar Burchardt)]

Package: autopkgtest
Version: 2.3.2
Severity: normal

Tests should be able to depend on the Build-Depends to be installed when they
are run, e.g. using

  Depends: @, ${source:Build-Depends}

This would be useful for Perl modules where the test suite is already run at
build time. Otherwise one would have to maintain another copy of those
dependencies: there are alread build, test and runtime dependencies in
Build-Depends, runtime dependencies in Depends. Having to maintain another list
of test-only dependencies in d/tests/control is not nice.

Ansgar