addContainerHook method

[knok]

http://www.namazu.org/pipermail/namazu-devel-ja/2005-November/000734.html

To detect some container file format, like MS Office Documents or OpenOffice?.org, I'll add a new method.

The followng is a pseudo code:

# func is a reference of function to handle a file.
$magic->addContainerHook("application/x-ole-storage", &func)