No boolean literals

[Victorious3]

`10` -> 10
`string` -> 'string'
`'long string'` -> 'long string'
`True` -> 'True'

Since number literals are passed on I would expect the same to happen for boolean literals, but instead they get converted to strings. The same happens for None as well. I can use 0 and 1 instead, but it's not really the same.

Workaround:

t_bool::bool = k_true @:`1` | k_false @:`0`;
t_bool_lit::Boolean = VALUE:t_bool;

[Victorious3]

Related: `0` ends up as {} in the generated parser. Probably some issue with implicit bool conversions.