Optimized ByteExtensions by replacing HasFlag() usage with bit masking

Increases performance significantly - many thanks to Mike Krueger for
suggesting this (many moons ago, although I am now just getting around
to testing it).
Regenerated documentation
Improved docs for TextPart and ParserOptions
Documented ParseException
Drop the use of Enum.HasFlag() in the date parser
Merge remote-tracking branch 'upstream/master'