Plug memory leaks on loading all modules
Fix wrong macro names

These macros can be used with not only listener but also general
modules.
Add missing "listener_" prefix
Add loader customizer mechanism
Use loaded loader customizers
Remove needless spaces
Add --enable-debug configure option
Handle unhandled C++ exception in test

GitHub: fix #8

I use loader-customizer new module mechanism instead of changing
cut-test.c. Because I want to avoid that libcutter depends on C++.

TODO: Iterated test isn't supported yet.

Suggested by Kazuhiro Yamato. Patch by Kazuhiro Yamato. Thanks!!!
Remove unused header include
Fix wrong assertion macro use