Fix c89 bugs reported by Cory Stup. Others may remain. I wasn't able to get gcc --std=c89 to build libevent at all, so I don't know what compiler the original reporter is using here. Note that this change requires us to disable the part of our rpc code that uses variadic macros when using a non-gcc compiler. This is a problem if we want our rpc api to be portable. svn:r1231