The binboy.mdx file is made up of a header followed by an entry
for each article.

Types
-----
Numbers are stored as a 4 byte int.

Strings are stored as a 4-byte length (int) followed by the actual
bytes in the string, if any.  The character string is not null-
terminated.

FILETIME is a standard Win32 structure containing a 64-bit value
representing the number of 100-nanosecond intervals since Jan 1,
1601.  Divide by 10,000,000 to convert to seconds.


The overall .mdx file format consists of a header followed by 0 or more records containing message-ids:

Header
Record
Record
Record
...


Predefined values
------------------
Signature = 0x36519861		// Signature identifying the type of file
Version = 1					// Current version


Header
--------------
int      Signature
int      Version
int      number of entries

... Message-Id records follow ...

Each Record
-------------
string      Message-Id without the enclosing .'<' and '>'
int			Flags.
FILETIME    Time the id was added.  Time is in 64-bit FILETIME format.


  Flag format
Bit    Meaning
--------------
0		Searched (Currently not actually used)
1		Header has been downloaded
2		Whole article has been downloaded.
3-31	Reserved