Getting ecm files from the ECM package

[Stephen Kelly]

Hello,

Soon I will be replacing code like

 find_package(KF5 REQUIRED CMake Compiler InstallDirs)

with 

 include(KDEInstallDirs)
 include(KDECMakeSettings)
 include(KDECompilerSettings)

As I've said before, it makes no sense that we have to find KF5 in order to 
build KF5, so I'm going to 'fix' that.

 http://thread.gmane.org/gmane.comp.kde.devel.frameworks/5860/focus=5976

(unfortunately the formatting of the reviewboard mail is no good. Visit the 
reviewboard site to read it).

find_package(KF5 ... ) will only be used to find KF5 frameworks.

After that's done, I'll be creating a kf5umbrella tier1 framework which 
installs a KF5Config.cmake and KF5ConfigVersion.cmake. This will work the 
same way as FindKF5.cmake currently works, and will be implemented similarly 
to Qt5Config.cmake - it is only used as a grouper, and is optional.

All the patches for this are already written for all the frameworks repos.

Thanks,

Steve.