Make solver information, stats available programmatically rather than just printing

So first of all, thank you for Roots.jl! This is a feature request to have some way through the public and documented API for the primary functions, e.g., find_zero to have the solver return information about the solution process, such as the reason for termination (e.g., did we stop because of convergence of f or of x?) and the number of steps taken. Perhaps this could be done through a different function name or by supplying a mutable solution data object argument, etc.