Recognition marker as enum

For better readability and avoiding magic numbers for the recognition method an enum should be introduced, something like:

enum class RecognitionMethod
{ 
    Casern,
    Hermes,
    NoMarker,
    Japan,
    MultiColor,
    Aruco
};

In some places (here control.h) already outdated comments can be found, where newer markers are missing:

// 0 == Kaserne, 1 == Hermes, 2 == Ohne, 3 == Color, 4 == Japan