Fix mzscheme static variable wrappers

$argnum needs to be expanded in the 'varin' typemap which shares
code used by the 'in' typemap.
Setting the static variable is also a function call (argnum=1).

Added class examples - needs static variables to work
Test newly working test cases with this fix

Examples/mzscheme/class/Makefile

@@ -0,0 +1,18 @@
+TOP        = ../..
+SWIGEXE    = $(TOP)/../swig
+SWIG_LIB_DIR = $(TOP)/../$(TOP_BUILDDIR_TO_TOP_SRCDIR)Lib
+CXXSRCS    = example.cxx
+TARGET     = example
+INTERFACE  = example.i
+SWIGOPT    =
+
+check: build
+	$(MAKE) -f $(TOP)/Makefile SRCDIR='$(SRCDIR)' mzscheme_run
+
+build:
+	$(MAKE) -f $(TOP)/Makefile SRCDIR='$(CXXSRCDIR)' CXXSRCS='$(CXXSRCS)' \
+	SWIG_LIB_DIR='$(SWIG_LIB_DIR)' SWIGEXE='$(SWIGEXE)' \
+	SWIGOPT='$(SWIGOPT)' TARGET='$(TARGET)' INTERFACE='$(INTERFACE)' mzscheme_cpp
+
+clean:
+	$(MAKE) -f $(TOP)/Makefile SRCDIR='$(SRCDIR)' mzscheme_clean