add cmake option to enable/disable example generation

[BenjaminBeichler]

fixes part of #23

Signed-off-by: Benjamin Beichler [email protected]

[BenjaminBeichler]

I have just done the trivial rebase for my old pull request. Are there any other obstacles ?

@maehne was in favor for this in #23, so maybe you can push it ;-)

[markfoodyburton]

As an interim solution, I'd go with this. (It would help).
Ideally we should move to a more 'cmake/ctest' way of doing things.

[BenjaminBeichler]

Yes, agree. But all the cmake files would need updates. I opted for the minimal invasive version.

[markfoodyburton]

(Actually there's work going on to fix it properly - should be merged soon :-) )