Handle the presence of NetworkManager 0.7 in KDE4 builds
*) Adapt MacroEnsureVersion.cmake to be able to check upper limits on version numbers
*) Adapt kdelibs/cmake/modules/FindNetworkManager.cmake to report the version found
*) Adapt kdebase/workspace/solid to select which version of NetworkManager support to build.
*) Move NM 0.6 and NM 0.7 support into separate directories.

NB This is build infrastructure only. There is no Solid backend for NM 0.7. Yet.