Allow directories in the source tree or build tree only if the
install tree is a subdirectory of the source tree or build tree,
as appropriate.
Re-use the test files in the RunCMake.include_directories test
to run in multiple scenarios. Bump the required CMake version
in the test to 3.0 to ensure that the new policy warnings are
emitted correctly.
Set the minimum required version of CMake high enough to avoid the
warning for CMAKE_LEGACY_CYGWIN_WIN32. The warning appears on stderr
and breaks the expected output matching.
This fixes a regression introduced in commit 290e92ad (Move
GetIncludeDirectories to cmGeneratorTarget, 2012-09-16) which loops over
cmGeneratorTargets before they get created, so the container is empty.
Stephen Kelly
Brad King