Sand variables

[leadinoto]

Added SANDRecoFiller for filling reco variables from SAND-reco output file

[chenel]

Thanks for making this PR!

The branch filling (in SANDRecoBranchFiller) appears fine to me. However, I don't think that adding SANDRecord.h directly into the CAFMaker's repository is the right way to do use it. I assume this header is copied from an equivalent SAND reconstruction package somewhere, right? If so, what we need to do is #include it from there. That way we don't mix dependencies. (And I especially don't want all the dictionary-related stuff at the bottom winding up in the CAFMaker library.) There's already some code in src/Makefile that adds some SAND stuff into the build if the right environment variables are set, and I think that should be used to obtain this file. Please remove the file from this branch. Thanks!