Gateway / CAS include issue

[Ralph Lange <Ralph.Lange@gmx.de>]

Hi.

Preparing to package the CA Gateway I find the Gateway needs casCtx.h (which in turn pulls in caHdrLargeArray.h), because it needs to know which event 
mask the exterior client used in a subscription.
casCtx.h and caHdrLargeArray.h are not installed as include files by CAS.

To make compilation work, the Gateway Makefile adds BASE/src/cas/generic to the include path.
Of course, this does not work nicely with binary packages, where the "...-dev" development package, which is a build dependency of the Gateway 
package, contains (installed) include files and libraries, but no sources.
What are the different stakeholders' opinions?

Is casCtx.h a public interface of CAS?
The Gateway is an important client app and undoubtedly needs it: Should it be made public? Or should the functionality rather be included in one of 
the existing public interfaces?
Should - as a workaround to allow packaging the Gateway- the epics-dev package just install the two header files?

Thanks,
~Ralph