http://vojgy5ep4wffmtpjmpnbpa4gq64bgn4yicuw6qmhbm6nqa2ysrva.b32.i2p/archive.html
The HTTP post received is not a mime-encoded post, but a fairly simple concatenation
of all of the data to be uploaded (with metadata messages first): POST /import.cgi\r\n
Content-length: $total\r\n
\r\n
$headerSize // 2 bytes
$header // $headerSize bytes, for authorization/etc
foreach (msg)
$msgFlags // 1 byte. 0x0 for normal posts, 0x1 for metadata posts
$msgSize // 4 bytes
$msgData // $msgSize bytes