Remove circular dependency between miscvis and avwutils

The fslanimate and sliceanimate scripts, currently in avwutils, introduce circular dependencies between avwutils and miscvis. They really belong here.

This MR is coupled with avwutils!10 (merged)

Note that the INC_PROB include directory has been changed to INC_CPROB, and -lprob to -lcprob, in line with config!6 (merged), although neither of these changes will have any effect on this specific project, because it does not directly include any libprob headers, and libcprob.a is sym-linked to libprob.a.