Interpose on select/pselect so that WebSockets sockets are only
reported as ready if they have enough to actually decode at least
1 byte of real data. This prevents hanging in read/recv after
WebSocket is reported as ready but is not actually ready because empty
frames or less than four base64 bytes have been received.

Split defines and constant defintions into wswrapper.h.

Cleanup debug output and add TRACE for more detailed tracing debug
output.

Major TODO is that select needs to timeout if WebSocket socket keeps
reporting ready but actually isn't ready. That condition will
currently hang forever because the select timeout value is not
adjusted when looping.