update TODO
update version number
Add return statement to CAPTURE_NULL

Since 'Throw' does not automatically return from a function, the
capturing code did not protect the function from working with
NULL pointers as array, resulting in segfaults.
Two versions of returning CAPTURE_NULL are now used, one for void
and one for non-void returning functions.
replace old capturing code
implement returning capture macros for gfunc3 init status
update capturing macros, improve exception handling and do some cleanup

- new returning capture macros for NULL and gfunc3 init status
- Try-Catch now effectively protects code from working with undefined array etc. (issue #8)
- remove code for second axis
improve exception handling

- add return statements to Throw macros
- use returning capture macros