* Catherine: so we'd like to propose a few minor API changes for `bits` (which will also be in place for `bitarray`, since they'll now share most of the code):

1. Remove the `bits(bits, length)` constructor that forcibly resizes bits to a different length, keep only `bits(bits)` (largely redundant with slicing, doesn't correspond to any Python interfaces)
2. Add `bits(bytes)` constructor without length, which defaults to `length=len(bytes)*8`
3. Make `bits(bytes, length)` constructor require `(length  + 7) // 8 == len(bytes)` and padding bits to be set to 0
4. Change `__eq__` to do strict type checking (both `bits('0011') == 3` and `bits('0011') == '0011'` will now return false
5. Remove support for `"0b"` and `"+"` prefixes in `bits(str)`, allow only `[01_\s]*`

any objections to those?