Foo.shell isn't named properly when using set_target_properties

[Adam Treat]

Hi,

For the Kst port I was having problems linking because kst's library (libkst) 
and executable (kst) share the same target name.  It seems that CMake doesn't 
support multiple targets with the same name even if they are of different 
types.

Looking at the documentation, it says that this can be fixed by calling the 
targets something different and then using:

  SET_TARGET_PROPERTIES(target1 target2 ...
                        PROPERTIES prop1 value1
                        prop2 value2 ...)

like so:

  SET_TARGET_PROPERTIES(fooexe PROPERTIES OUTPUT_NAME foo)

This works well, but the resultant file for launching is named 'fooexe.shell' 
and it calls tries to call a non-existent 'fooexe' ...

Cheers,
Adam