a5ccb22a3d
In this first cut, a raw parcel is parsed to check that the overall format is correct. At the same time, we record the metadata seen and their position in the parcel for later retrieval using the get* methods. This means that the 'has' method to check the existence of a metadata should work. Removed size and iterator methods. Instead, I added a new method to give access to the set of keys. The user can make use of the set to call size(), empty(), iterator() etc...