Fixes to make work with TCP sockets. Disabled features from sys/uio.h which are just stubbed out, removed hardcoded use of ki_pipe (I previously wasn't properly initializing something in my use case which caused the empty stub to be used). Tweaked configure script to remove warnings about preprocessor/compiler mismatches.
Merge branch 'master' of github.com:mattiasbergbom/libevent-nacl-port