Correct handling of tag name and changeset author in sf-tag-hg-code Addition of sf-push-hg-tags and associated template file, for pushing the tags created in sf-tag-hg-code back out to the MCL. Minor whitespace rationalisation.

Added specification of changeset author when committing. Removed execution of hg out - that's taken care of in the push tags target/template.

Fix: package build fail because there is no package_definitions dir

Introduced new Helium property (sf.spec.ats.version) to specify ATS version