scilab: change swig options, new option -gatewayxml, remove -internalmodule
scilab: generate gateway source with swig
scilab: fix segmentation fault
scilab: fix generated gateway source (missing include, entry point name)
scilab: swig generates loader script
scilab: fix gateway entry point name
scilab: build now examples/tests with standard tools in (no more builder.sce)
scilab: fix matrix2 example module name
scilab: fix test-suite makefiles and util scripts for standard build tools