Remote whitespace at the ends of lines. Remove blank lines from the ends of files. Change modes on source files so that they are not executable. Signed-off-by: Dan Cross <cross@gajendra.net>

distinguish between "cannot receive without blocking" and "EOF on connection". In libmux, do not elect async guys muxers, so that synchronous RPC calls run in the main event loop (e.g., in eresized) do not get stuck. Fixes problem reported by Lu Xuxiao, namely that jpg etc. would spin at 100% cpu usage.

in case the response comes back and another thread tries to give it to us, all before we are enqueued.