Container special type
There are some container formats. The easiest example is an archive: it contains files of any type. We may want to indicate that the type of the chunk of memory is any format which should be parsed. It may be useful for some applications like kaitai-powered binwalk parsing everything in the file.

So I propose to add a special built-in type which instantiation should pass the control flow to an algorithm which will try to match the blob against all the signatures (see #225) in the library, if it matches - tries to parse it, if it parses (including passing all the checks #81) - then assumes that the format is guessed correctly.

Obviously it will require RTTI in C++.

I don't know any good name for this kind of type. ```container``` maybe, or ```signature_matcher```, but I don't really like the mentioned names.