Used "pipe" to simplify header name translation & tokenizer construction

Added support for spreadsheet-style alpha ID column headers (num2id,
id2num, get_ids, add_alphaids), Header.translation, an OrderedDict
attribute was added to allow translations functions to be more easily
organized, seen, modified and/or customized; processing is performed by
the munge_headers method.  Header.tokenizers, an OrderedDict attribute
was added to allow similar ease of use for building the header parser
functions, execution is performed by the build_parser method.