new bitOrder byteOrder combimation

[mbeckerle]

Previously disallowed combination to be allowed.

[mbeckerle]

Here is a well-documented use case for this.

The Asterix CAT 034 message uses byteOrder bigEndian but bit order leastSignificantBitFirst for numbers that span bytes. For example they describe an 11-bit integer in this way:

In this picture you can see they are numbering the bits from the right, leastSignificantBitFirst starting from 1. But the COUNTER field spans all of Octet 3, but also includes the least significant 3 bits of Octet 2. In those least significant 3 bits are the most significant (numerically) 3 bits of the 11 bit COUNTER integer, so this is bigEndian byte order, but leastSignificantBitFirst bit order.