Fix: package build fail because there is no package_definitions dir

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

Changed locations of package_definitions to make the files a little bit more usable

Added call to produce package definition peices from system definition(s).

Enabled tool to create arbitrarily deep paths for output

Added a few strategically placed spaces, to improve the indentation of the output.

Merge in tools for manipulating sytem defintions from their own repo.

Move files into a directory appropriate for merging into main config repo.

updated commit message as no longer triggered by change in packages repo

Separate the generation of the system model and the generation of the derived package definition into 2 script so can be run separately

change destination directory for auto generated model to sydefs\auto

Fix all symbian3 package_definition have disappeared from packages

Fix: update back to HighFidelityModel is not possible because there are changed files and it crosses branches

Exec hg add/addremove commands before hg diff