64 bit support

EPICS 3.14.12 patches. problem: different installation order of libs for vxWorks. Now don't link non-munch libs.
Warning for non-existing cross compiler
Don't link dbd directory any more. Not needed with current version of require.
No more undefined symbols for prerequisites any more in order to support loading of test versions instead.
Use generic lib suffixes in order to support other OS types.
Fix wrong export for registrars.