rose.run: move source version file generator.

The logic is now in its own function in `rose.run_source_vc`.
This should provide a starting point for #382.
Merge branch 'master' into 382.source_vc_info
Merge branch 'master' into 382.source_vc_info
Merge branch 'master' into 382.source_vc_info
Merge branch 'master' into 382.source_vc_info
Merge branch 'master' into 382.source_vc_info
Merge branch 'master' into 382.source_vc_info
Merge branch 'master' into 382.source_vc_info
Merge branch 'master' into 382.source_vc_info
Merge branch 'master' into 382.source_vc_info
Merge branch 'master' into 382.source_vc_info
Merge branch 'master' into 382.source_vc_info
Merge branch 'master' into 382.source_vc_info
Merge branch 'master' into 382.source_vc_info
Merge branch 'master' into 382.source_vc_info
Merge branch 'master' into 382.source_vc_info
rosie: remove format=json from URL.

Also some tidy up.
rose edit: ignore rose-meta.conf root level confs.

Instead of dying with a traceback.
Merge branch 'master' into 382.source_vc_info
Merge branch 'master' into 459.rosie.format=json