Bug#844531: mh_depends: Generate ${maven:Depends} Accorfing to *.poms

[殷啟聰]

Source: maven-repo-helper
Version: 1.9.2
Severity: wishlist

maven-repo-helper should contain a program `mh_depends` which by
examining the POMs in a `.poms` file and generate a ${maven:Depends}
or even ${maven:DocDepends}.

There are a couple of benefits of using mh_depends instead of
mh_resolve_dependencies:

1. It is independent from maven-debian-helper so that packages built
by Gradle or Ant can make use of it without installing
maven-debian-helper. I tried using it alone in one of my Gradle-built
packages and it failed.

2. mh_resolve_dependencies always force create maven.rules,
maven.ignoreRules and other maven.*Rules, and reformats and add
comments to the *.poms and maven.*Rules whenever processes them, which
is not a good experience.

I spotted that there is a class [1] about substvars in
maven-repo-helper. Is that the initial work of this idea?

[1]: https://anonscm.debian.org/cgit/pkg-java/maven-repo-helper.git/tree/src/main/java/org/debian/maven/repo/Substvars.java?h=debian/1.9.2