Manual corrections

[Arthur Schwarz]

A few little nit-noys (%language "C++"):
1: %define api.position.type is not defined in Section 3.7.13
2: %define api.position.type {type} should be api.position.type type.
3: %define api.position.type type causes Bison to generate the following message
   x.y:9.9-25: error: %define variable 'api.position.type' is not used
4: %define api.location.type {type} should be api.location.type type.
5: %define api.prefix {prefix} should be api.prefix prefix.