Linux wb_set_blocking bug.
wb_set_blocking was always setting the socket to non-blocking on Linux.
This was causing large-ish files to fail in the send_fully() function
because send() was failing with EAGAIN. I haven't tested this fix on other
Unix type platforms - just Linux 13.10.
Merge pull request #14 from mikesart/wb_set_blocking

Fix Linux wb_set_blocking bug.