source syncing ftl - Added 'sf.spec.sourcesync.archive' preference to do 'hg archive' instead of 'hg sync'. If set and the repo sync is s'posed to be synced by tag it still does the slower clone+update behaviour.

platform build - added 'sf.os.compile.iterate' variable to iterate though the main targets rather than all at once to work around raptor problems with single model.