#1 Check return codes everywhere

[Markus Elfring]

A few checks for return codes are missing.

Examples:
Would you like to add more error handling for return values from "malloc" like in the function "pymodule_initmodule" and "camlwrap"?
http://pycaml.cvs.sourceforge.net/viewvc/pycaml/pycaml/pycaml_ml.c?revision=1.1&view=markup