fixed buffering and added baud rate option

[zcsahok]

Fixed limited UDP read length and buffering of text while sending.

Switched to select-based timeout for UDP receive. This allows fine granular control and the timeout is set to 50 ms, which gives a maximum keyer data rate ~20 cps.
As 24 wpm is ~2 cps this is high enough not to cause buffer underflow and at the same time low enough to be able to react on "buffer 2/3 full" signal (round trip time is ~20 ms as it takes 10 ms to transfer a char @ 1200 Baud).

In/decrease speed in 2 wpm steps, conforming to cwdaemon.

Added baud rate setting. Could be needed for non original keyers.

Added use strict and using Data::Dumper to display datagram in debug mode.

Selecting printable chars was changed to regexp. It is easier to read than raw ASCII codes.

Added pot value reporting in debug mode. All status bits are evaluated and reported.

Also updated the man page. (still needs fixes, e.g. reset is not supported)

Tested with K3NG keyer.

edit: this PR fixes #1

[N0NB]

I made an amendment to the patch to add the change to the daemon file. I've pushed the new code. Thanks!