Allow to define excludes for the ContentPackageArchiver to prevent copying of script files from src to target

Similar to the maven-war-plugin it should be possible to define exclusion filename patterns of files which should never end up in the filevault package (compare with https://maven.apache.org/plugins/maven-war-plugin/war-mojo.html, parameter warSourceExcludes).
The following filenames come to my mind, which would be useful to exclude by default:

1. .DS_Store
2. SVN files
3. Git fles
4. FileVault conflict files

That way it would be possible to create the package based on the source directory without being forced to first use the maven-resource-plugin to copy them somewhere to /target and do the filtering there.
That would speed up the generation of large packages a lot.

At the same time the default value of parameter builtContentDirectory could be modified to point to the source directory e.g. ${basedir}/src/main/jcr_root.