DiffEq skips over event in the first `solve` but works after `reinit!`

[ChrisRackauckas]

@cuihantao

There is a total of 645 allocations: 32.42 KiB. The optimization example here (Code Optimization for Differential Equations · DifferentialEquations.jl) only has 41 allocations. Is my allocation number normal?

A lot of those allocations are just saving the time series. I think there’s some more in the callback code that I need to eliminate though.