[CMake] Convenience Libraries and Precompiled Headers

[James Mansion]

>Conv. libs are not (officially) supported by cmake. Just
>compile all source files into the resulting library. That's
>what we do for KDE.

Oh, tht's a shame.  I was hoping to be able to use a single
structure which would build static or dynamic libs as either
multiple small libraries or one big one, selectable, without
having any duplication of lists of sources etc.

James