Revert previous commit, and remove the <event.h> symlink.  As this is a system-specific extension, not a standardized interface, it should be located with the sys/ includes.
Revert previous commit, and remove the <event.h> symlink.  As this is
a system-specific extension, not a standardized interface, it should
be located with the sys/ includes.

Requested by:	wollman

jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase