#76 autodhs makefile might be vulnerable to a bad loop

[Lee Worden]

the merge rules are intended to be called with a compound basename, like keir52fl.kear51fl.merge.RData - this will create a dataset by merging the "IR" and "AR" datasets. If called with an incoherent construction like keir52fl.merge.RData it's possible that it might create an infinite recursion by making a .R that depends on its own .RData or something. Need to check.