MCMCDyn preallocates the space for logging toggles; should it be (re)allocated dynamically?

[krivit]

MCMCDyn_wrapper() pre-allocates three integer vectors (time, tail, head), each of length control$MCMC.maxchanges, then trims them as needed. A more memory-efficient approach would be to start with a short vector and use array-doubling, either using Realloc() and then allocating the R vectors as a final step or working with R vectors and copying as needed.