scripts/combo-layer: make init set up initial component data
The "init" subcommand will now copy the current state of each component
repository into the combo layer repository, set last_revision for each
component, and then use "git add" to set up the initial commit (but will
not actually make the initial commit - that is left up to the user).
Also take the opportunity to bump the version number.
Signed-off-by: Paul Eggleton <paul.eggleton@linux.intel.com>
