Silence int to bool warnings (following standard_wide definitions)

Signed-off-by: K-ballo <k@fusionfenix.com>
Make the as_spirit_parser fallback the worst possible match (breaks MSVC)

Signed-off-by: K-ballo <k@fusionfenix.com>
Added `Context` parameter to attribute_of

Signed-off-by: K-ballo <k@fusionfenix.com>
lexeme, no_skip, skip

Signed-off-by: K-ballo <k@fusionfenix.com>