SWIG: Make gem5 compile and link with swig 2.0.4

To make gem5 compile and run with swig 2.0.4 a few minor fixes are
necessary, the fail label issues by swig must not be treated as an
error by gcc (tested with gcc 4.2.1), and the vector wrappers must
have SWIGPY_SLICE_ARG defined which happens in pycontainer.swg,
included through std_container.i. By adding the aforementioned include
to the vector wrappers everything seems to work.

util/regress all passing (disregarding t1000 and eio)