Allow custom list of Git clean excludes, workspace excludes and pickup tar-ignore from debian/source/options
Allow custom list of Git clean excludes, workspace excludes and pickup tar-ignore from debian/source/options

New environment variables:

GIT_CLEANUP_EXCLUDES
	Specify a ':' separated list of file paths to ignore when performing
	a Git cleanup. This allows to keep generated files and transfer them
	into the source package.

	Example: GIT_CLEANUP_EXCLUDES="debian/dependency-cache:build.conf"

WS_CLEANUP_EXCLUDES
	Specify a ':' separated list of file paths to ignore when performing
	the workspace cleanup. This allows to keep generated artifacts for
	archiving in Jenkins, e.g. for cases where generate-git-snapshot is
	only one step in the build process.

By default, generate-git-snapshot uses the -I option for dpkg-buildpackage.
This overrides what one may have specified in the debian/source/options.

webtrekk-kane/jenkins-debian-glue,webtrekk-kane/jenkins-debian-glue