Generalize oderkf to support orders != 5. Add ode23_bs based on oderkf.
Add performance comparison for adaptive solvers.
Some cosmetics & new test added (B5).
Devectorization in oderkf, oderosenbrock and ode_ms (fixes problems related to JuliaLang/julia#6118).
Cleaned up performance test.
Added backward propagation in oderkf (part of #2).
Remove performance test for now.
Merge pull request #16 from acroy/oderkf

WIP: Generalize oderkf to eventually replace ode23