This is giving me major headaches! I'm having trouble even describing the problem in words.

Basically, I want to be able to manage a core library (coreLib) of Actionscript classes with the following requirements:

* latest version is checked out when a new project starts.
* a dev can make changes to the coreLib and then commit them back into the repo as project is written (maybe bug-fixes, added features, etc.)
* the project contains a 'snapshot' of the coreLib so that, if returned to months later, it (as automatically as possible) has a copy of the coreLib that has guaranteed compatibility with the project.

I tried using externals but this can break compatibility going backwards. I'm currently exporting the coreLib into the project and its VC'd along with the project. I can't figure out how to get the changes back into the repo though, without just copying over the top and losing history.

Any advice?