scripts: Move scripts code into separate sources

Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
scripts: Use numeric script names

Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
scripts: Use numeric action val in RPC notifications

Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
service: Do one exit point from cr_service_work

That's preparation to "several requests per connection" patch.

Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
service: Allow to server more requests after page-server start

The problem with several requests is that criu leaks resources after
doing dump/restore. It's OK since process exits anyway, but for
multy requests per connection it's better to audit this thing.

For now -- allow to do requests after the page-server-start one only.

Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
page-server: Don't setup options in parent task

When service starts page server all the preparations (log, wdir, img dir, etc.)
happen in parent task, then we fork page server.

This is OK for now, but when we will serve several requests per connection, all
these resources would be leaked in parent.

Signed-off-by: Pavel Emelyanov <xemul@parallels.com>