Improved symbolic capabilities of dominant eigenvalue function

Two new utility function in the private directory: maxsym() and minsym(). These attempt to find the max and min of symbolic arrays. The update to shc_lv_lambda_us() uses these.

Signed-off-by: Andrew D. Horchler <adh9@case.edu>
Noise index shifted in global passage time function

shc_lv_globalpassagetime() now shifts the index of the Epsilon input internally such that Epsilon(i) = Epsilon(i+1).

Signed-off-by: Andrew D. Horchler <adh9@case.edu>
Fixes to non-uniform case of mean period constant finding function

Some things had no been adjusted since the change from finding the neighborhood size. More fixes may be needed. I'm not sure about the starting index and  if the output always get properly shifted.

Signed-off-by: Andrew D. Horchler <adh9@case.edu>