Consider support of multiple message code schemas

[clavecoder]

Short form 0: 32 bit

Standard form 1: 64 bit.

Intermediate form 2: 96 bit.

Long form 3: 128 bit.

Examples:

00101C01

0010 1C01

0 01 01 C 01

1000 0101 02CC 0001

10 0001 01 02 C C 0001


1000010102CC0001

1000 0101 02CC 0001

10 0001 01 02 C C 0001


20000001001001CC00000001

2000 0001 0010 01CC 0000 0001         

20 000001 001 001 C C 00000001


3000000001000001000001CC00000001

3000 0000 0100 0001 0000 01CC 0000 0001

3000 000001 000001 000001 C C 00000001