major revision of the template function body for the bitfield operators
more options for bitfield operators, such as the possibility to specify an NA-value and the position in the bitfield, and a custom description
more stringent provenance handling, now provenance is reported as a combination of the Action name and the parameters that are used (following PROV terminology and logic)
revision of the bf_decode() output reporting, now with a more user-friendly return value
full documentation and functionality of all functions (except auto determination of floating-point encoding for numeric values)
document also MD5 checksum for registries
bitfield 0.2.0
revise various functions
improve text (readme/vignette)
change naming of the functions
correct terminology, the class is not the bitfield but instead an array or registry that contains information about the bitfield. Hence, I renamed it to registry
use attributes to capture a bitflag description and name