Fix cpplint warning about missing sources in Stapling

Our cpplint check wasn't finding Stapling.cpp and SerializedStapling.cpp
in the CMakeLists.txt. This is just because the cpp files were listed on
their own line. This change puts them on their own line so cpplint can
find them.
Add setLocalActive and isLocalActive to components

To avoid confusion between setActive and isActive, a getLocalActive and
isLocalActive is added to for the active state of the component. While
isActive (still) returns true if the component is active and
SceneElement is active. This naming follows the getPose get/setLocalPose
of the Representation.