bump version number
bump version number

5.8 now in monodevelop master
fsharp/xamarin-monodevelop-fsharp-addin,nosami/xamarin-monodevelop-fsharp-addin,nosami/xamarin-monodevelop-fsharp-addin,fsharp/fsharpbinding,Ming-Tang/fsharpbinding,fsharp/xamarin-monodevelop-fsharp-addin,Ming-Tang/fsharpbinding,fsharp/fsharpbinding,fsharp/fsharpbinding,Ming-Tang/fsharpbinding