Add options.ctol to prima_is_success

[nbelakovski]

This was discussed in the Python binding PR but not implemented. Something that would need to change to accommodate this would be setting the default options.ctol in C to sqrt(eps), which means we could no longer pass it to Fortran as an optional parameter.

Alternatively, in prima_is_success we could check if option.ctol is NaN and use sqrt(eps) if so, but I seem to recall there were some issues with NaN checks with certain compilers and options?

[zaikunzhang]

I see the issue ...