allow anonymous structs within parents
hack in array support for bitfields
make sure array bitfields get enough data for full count
big overhaul intended to reduce copy-pasta between arrayizeField and _.struct paths, by way of eliminating buffer slicing and making bitfields more consistent with normal fields. adds an (intentionally undocumented at this point) optional offset field to read/write methods
update version for arrayize-able bitfields and internal refactor