Using CMake .gitexternal

Change-Id: I02f2ec38a0586b927d1068a1bff67e9f4c6d7461
Fixing cppcheck warnings and cleaning top-level CMakeLists

Change-Id: I58205203e168a2fdc59bdf59ecc17dc188dbe747
Fixing CPack config - desktopstreamer packaging on debian

Change-Id: Ibaae72754c60147237e335b943377db00818decb
Merge pull request #70 from rdumusc/gitexternals

Using .gitexternals for the Eyescale CMake subtree