version 1.06: integrated code from Util.pm into EntrezGene.pm.
              changed packaging to Perl standard
              changed next_seq() default option to 2, so now the call
                $parser->next_seq() is equivalent to the call
                $parser->next_seq(2) in version 1.05
              updated documentation to reflect all changes  

version 1.05: added support to parse the NCBI 4/5/2005 download, which
              inexplicably added a useless space before ',' on all lines, broke
              some lines into two yet condensed others (brackets) to one line.
              This unfortunately slows down my parser because I have to use
              lookahead regexes to fix the parser for this weird new format.
              I also fixed a minor mistake in error reporting function

version 1.04: added attempt at opening large file (2 GB) on Perl that does
              not support it; added 'file' option to new(); added file
              name in error reporting message; updated documentation

version 1.03: added validating capability such that anything that does not
              conform to the current NCBI Entrez Gene ASN.1 format would
              raise error and stops program. Position of the offending
              data item would be reported.

version 1.02: added input_file function that accepts filename input, and
              next_seq function that returns the next record

version 1.01: unescaped double quote escapes in double quoted strings

version 1.0: released