Update contributor
Add test cases for Bisection. Add termination condition to Bisection.

Add all test cases from
http://www.polymath-software.com/library/problemlist.shtml for
Bisection.
Add termination condition to Bisection.TryFindRoot for faster
termination in case the accuracy cannot be improved further.
Add test cases for Brent. Add termination condition to Brent.

Add all test cases from
http://www.polymath-software.com/library/problemlist.shtml for Brent.
Add termination condition to Brent.TryFindRoot for faster termination in
case the accuracy cannot be improved further.
Add further roots to BisectionTest.Oneeq18a.
RootFinding: Add fallback to Bisection in FindRoots.OfFunction.

Add fallback to Bisection in FindRoots.OfFunction.
Add test cases for FindRoots.OfFunction.
RootFinding: OfFunctionAndDerivative fall back to Bisection instead of Brent (more robust)
RootFinding: FindRoots functions with optional maxIterations argument