Enforce the order of MSC data-packages

[dexX7]

I suggest to temporarily insert a line in the spec that Mastercoin data packages should be in order within an output:

Sender's pubKey
Mastercoin data-package 1
Mastercoin data-package 2

It appears that data-packages are only parsed correctly, if this order is given and allowing unordered data packages is probably not trivial. See the discussion here: https://bitcointalk.org/index.php?topic=292628.msg5646781#msg5646781 (and a few posts earlier)

Edit: to cover transactions that are already out which don't fit exactly in the schema "sender-pubKey, data 1, data 2", I suggest to specify the handling of data-packages with something like "use the longest sequence of MSC data-packages within a transaction's output with ascending sequence numbers, starting from 01 and in the case that multiple multisig outputs are available, the same should apply, but starting from last-seq-num + 1", example:

Output 1:

Pos 0: junk
Pos 1: junk, seq num 01 (appearingly)
Pos 2: junk
Pos 3: Mastercoin data-package, seq num 01
Pos 4: Mastercoin data-package, seq num 02
Pos 5: junk

Longest sequence is pos 3 + pos 4, so take them.

Output 2:

Pos 6: junk
Pos 7: Mastercoin data-package, seq num 03
Pos 8: Mastercoin data-package, seq num 04
Pos 9: Mastercoin data-package, seq num 05

The longest sequence starting with a sequence number of 2 + 1 = 03 starts at pos 7 and ends with pos 9. So the actual data-stream is within pos 3, 4, 7, 8, 9. Of course it's a somewhat unrealistic example, but to give you an idea.

Edit 2: more or less done, see: https://bitcointalk.org/index.php?topic=292628.msg5652293#msg5652293 for the minimal changes.