lo_cpp.h include of <cassert> in the middle of namespace causes build failures

[cme]

lo_cpp.h has a #include <cassert> inside the lo namespace declaration, which results in the necessary declarations being inaccessible to anything that includes lo_cpp.h before its own inclusion of <cassert> due to the preprocessor multiple-inclusion guard.

I've submitted #99 as a suggested fix, moving the necessary #include to the top of the file and leaving the rest of the declarations in place.

[radarsat1]

Thank you!