Apparently g++ 4.5.2 on native mingw32 inserts references to __Unwind_Resume
when exceptions are supported. This function is not present in the g++ 4.4
cross-compiler found in Debian, leading to linker errors when cross-
compiling. So we use the latter to build CppUnit itself.

Another problem arises with g++ 4.4, which is the incomplete stripping of
exceptions when -fno-exceptions is used. Since ExceptionTestCaseDecorator.h
has such code, we protect it with #ifdef __EXCEPTIONS in the meantime.