Log Message:
"Oops."  BUILDLINK_DEPMETHOD.libevent was defaulting to \ 
"build", which is
no longer correct since update to libevent 1.x; it now uses libtool and
generates a shlib.

Remove the offending bl3 line, and bump all dependents' PKGREVISIONs, since
the binary pkg changes for any OS that doesn't have a sufficient builtin
libevent version (or the package has requested a non-builtin version).