Add Swig_obligatory_macros which must be called by each
target language to define SWIG_VERSION correctly
in the generated code, as well as the language specific
macro SWIGXXX where XXX is the target language name.
Drop the #ifdef SWIGXXX that was previously generated -
I can't see the point of this and if users are defining
this macro somehow, then users will need to change this
Closes#1050
Ensure that SWIG_VERSION is defined both at SWIG-time and in the
generated C/C++ wrapper code (it was only defined in the wrapper
for some target languages previously).
SWIGGO and SWIGJAVASCRIPT are now defined in the generated wrappers
to match behaviour for all other target languages.
Stop defining SWIGVERSION in the wrapper. This only happened as a
side-effect of how SWIG_VERSION was defined but was never documented and
is redundant.
The new testcase also checks that SWIG is defined at SWIG-time but not
in the generated wrapper, and that exactly one of a list of
target-language specific macros is defined.
Fixes#1050
