Protocol spoken by the submit server
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

(1) Server sends "+OK\n" or "+TLS\n"

(2) TLS is started if requested

(3) Client sends hello, server replies

(4) Loop: client sends command, server replies

Except for the initial "+xxx" message, all requests and replies are simple objects
as handled by the Sherlock library. Each line starts with a single-character
attribute name followed by the value of the attribute, the object is terminated
by an empty line. Parentheses can delimit nested blocks.

Every reply contains either a "+" or "-" attribute denoting status (OK/failed).
The value of the attribute is a message for the user, which should not be
interpreted in any way.

Hello request:

	Uusername

Hello reply:

	(only status)

Submit request:

	!SUBMIT
	Ttask
	Ppart			<-- optional part ID
	Ssize
	Xextension
	(after the request is ACK-ed, the client sends raw data and then server sends a 2nd reply)

Submit reply:

	(only status)

Submit reply after data:

	(only status)

Status request:

	!STATUS

Status reply:

	task status objects defined below with the following added:
	(T
		Aallowed_extension
	)

NOP request:

	!NOP

NOP reply:

	(only status)


Task status objects
~~~~~~~~~~~~~~~~~~~
(T				<-- task
	Tname
	(P			<-- task part
		Pname
		Vid		<-- which version is current
		(V		<-- submitted version
			Vid
			Tsubmit_time
			Sstatus
			Lfilesize
			Hhash
			Xextension
		)
	)
)