add .IsSerializable checks for F# union/record/exception types
add .IsSerializable checks for F# union/record/exception types

cloudRoutine/Unity3d.FsPickler,haraldsteinlechner/FsPickler,nessos/FsPickler,nessos/FsPickler,mbraceproject/FsPickler,wallymathieu/FsPickler,wallymathieu/FsPickler,FsUnity/Unity3d.FsPickler,FsUnity/Unity3d.FsPickler,cloudRoutine/Unity3d.FsPickler,haraldsteinlechner/FsPickler