[CMake] swig

[Brad King]

Anton Deguet wrote:
> I would link this request/bug to two others:
> - bug #1740 (closed since duplicate, but I believe parts of the
> discussion are relevant)
> - bug #1731 (similar problem)
> 
> The addition of a DEPENDS_SCANNER is obviously a more flexible,
> powerful, extensible solution.  The SWIG related tickets could then
> easily be solved by setting  DEPENDS_SCANNER to "swig -MM".  Isn't that
> a good reason to move this feature implementation a bit higher on the
> priority list? :-)

I've updated the corresponding bug report:

http://www.cmake.org/Bug/bug.php?op=show&bugid=2172

to reference those other two bugs.  #1731 has been closed as a duplicate 
of the more general #2172.

I've also put the DEPENDS_SCANNER idea into the bug's discussion with a 
partial implementation description.

-Brad