Bug#1005324: ITP: valgrind-if-available -- dependency package to pull in Valgrind if it's available

[Adam Borowski <kilobyte@angband.pl>]

Package: wnpp
Severity: wishlist
Owner: Adam Borowski <kilobyte@angband.pl>
X-Debbugs-Cc: debian-devel@lists.debian.org

* Package name    : valgrind-if-available
  Description     : dependency package to pull in Valgrind if it's available
 This metapackage installs Valgrind on architectures where it is available.
 As the list of archs where Valgrind works changes quite often, explicitely
 listing it as a [Build-]Depend is cumbersome and prone to being outdated.
 Instead, you may use this metapackage.

It's basically a Build-Recommend, except for doing the right thing during
temporary non-installability of valgrind (ie, your package will wait in
BD-Uninstallable if valgrind is _supposed_ to be available).

There's a crapload of packages that B-Dep on valgrind on some arches, every
one manually listing them.  This is tedious.

This metapackage could be built from src:valgrind, but conditionalizing
every bit of build is tricky (all normal stuff needs to be suppressed). 
This separate source brings one instance of redundant list, but has less
moving parts.