Add option to ignore broken symlinks in directories

[DimitriosSG]

When using the "directory" src type, the plugin fails with the following error when it encounters a broken symlink:
Caused by: java.io.FileNotFoundException: <filepath> (No such file or directory)
Most other maven plugins (for example the rpm-maven-plugin and maven-assembly-plugin) ignore any broken symlinks and process the rest of the directory.

When building large projects with lots of dependencies, there is a change one of them has a broken symlink somewhere, so plugins should be able to deal with it (by ignoring the broken symlink), or at least have an option to do that.

I can workaround the issue by first packaging the stuff I want into a tgz (using maven-assembly-plugin) and then using that as the src for jdeb, but jdeb should exhibit a behavior that's consistent with other maven plugins.

I've also attached my plugin configuration (project-specific and company-specific identifiers removed)
jdeb.txt

[tcurdt]

Sounds like a useful addition. Just needs someone to implement it. Does not sound too hard.