[cmake-developers] LINK_LIBRARIES property topic

[Brad King]

Steve,

I've reviewed this topic:

 4cf80cc Make sure types match exacty without conversion when making std::pairs.
 786aa36 Fix (hopefully) the Mac build.
 9bb1f54 Populate the LINK_LIBRARIES property when linking to targets.
 1381d56 Add a HEAD-target to target linking API.

I'm hesitant to use

 std::pair<cmTarget*, std::string>

as a map key.  I had to read the commit history of it to understand
what it represents.  Please use a helper struct with a suitable name
instead.  Then squash the fixup commits back into the main HEAD-target
commit.

Also, I see a few uses of GetOriginalLinkLibraries left.  The only one
we should have left is the one for the CMP0003 OLD behavior.

Thanks,
-Brad