Resolve conflict in Source/cmTarget.cxx by integrating the changes to
the internal copy constructor from both sides.  Also resolve a logical
conflict by dropping the special case for INTERFACE_LIBRARY targets.
Since cmTarget::SetMakefile already forces CMP0022 to NEW for such
targets we need no special handling.

Resolve conflict in Source/cmTargetLinkLibrariesCommand.h by dropping
the documentation change.  We will make the same change in the new
location of the same documentation in a separate commit.

Resolve conflicts in

 Tests/RunCMake/CMP0022/CMP0022-WARN-empty-old-stderr.txt
 Tests/RunCMake/CMP0022/RunCMakeTest.cmake

by taking the side from the 'policy-CMP0022-fixes' branch.