Inconsistent API: fill(), octet(), and fromHex() are little-endian. Everything else is big-endian.

[jamesrom]

• fill() appends 0's to the end of the array, instead of prepending.
• octet() is just shorthand for fill(8) so it suffers the same issue.
• fromHex('F0') returns [0, 0, 0, 0, 1, 1, 1, 1], instead of [1, 1, 1, 1, 0, 0, 0, 0].

[YoshGuenther]

toNumber() is little-endian as well.