Possibilities of supporting 2.0.1+ clients

[MrMarvin]

Hi @shirsig, first of all thank you very much for this and you other addons! They make playing on old clients a great experience!

In the light of certain realms slowly transitioning over to TBC content, I was looking into taking my accustomed look and feel of todays highly modified client interfaces over to the 2.4.3 client. Currently SortBags master branch does not support 2.0.1+ clients.

While I was able to fix the most prominent issues, in its current form however this break backwards compatibility. Here's my fork: https://github.com/MrMarvin/SortBags-tbc

I would be more than happy to work out a solution that supports both client versions, however due to the LUA 5.0 to 5.1 changes, it seems unlikely to happen. Especially the compatible use of varargs for set() and union() is impossible to my knowledge.
Do you have any idea or preference how to go on with this?