Fixed build for http date grammar.
Simplified http parser class.
Implemented error handling, parsing and lexer of http date parser.
Simplified status code setting in http parser.
Http date parser is now more tolerant.
Implemented feedback of date and time as epoch times.
Renamed httpdateparser -> http_date_parser.
Added performance tests for http date parser.
Added unit tests for http date parser.
Simplified the day_of_the_year function.
Added unit tests for http date parser.
Implemented date header in request interface.
Fixed httpdate for older bison versions.