Version v2.2.7 - Additional setter / getter combo

What's new:

1. Added getter for custom properties of Blob:

// Simple blob implementation
func (b *SimpleBlobie) GetPropetry(key string) (interface{}, bool) {
	v, ok := b.customProperties[key]
	return v, ok
}
// Kalman filter based blob implementation
func (b *KalmanBlobie) GetPropetry(key string) (interface{}, bool) {
	v, ok := b.customProperties[key]
	return v, ok
}

2. Added setter for custom properties of Blob:

// Simple blob implementation
func (b *SimpleBlobie) SetPropetry(key string, value interface{}) {
	b.customProperties[key] = value
}
// Kalman filter based blob implementation
func (b *KalmanBlobie) SetPropetry(key string, value interface{}) {
	b.customProperties[key] = value
}