Refactored the backend code/API's to support 'meta' strips (i.e. strips containing other strips). These have been implemented to be nested to 'unlimited' depths (in terms of common usages that is, though there is a very remote chance of stack-overflow in theoretrical evil cases only that shouldn't ever be encountered in production).
This paves the way for implementing the necessary tweaks needed for the transform code (in addition to some cool user-level tricks)
Joshua Leung
f87fcde686