add escape_char function

Signed-off-by: etienne <etienne.basset@ensta.org>
fix typo that leads to no include

Signed-off-by: etienne <etienne.basset@ensta.org>
add support for : ? (match 0 or 1 times), '+' match 1 or more times

Signed-off-by: etienne <etienne.basset@ensta.org>