Explicitly request host byte order in pcmcat

[argilo]

As noted in ka9q/ka9q-radio#66, ka9q-radio recently changed pcmcat's behaviour with respect to network-to-host byte order conversions.

Previously, a network-to-host byte order conversion was always performed by default, and could be turned off with the -b flag.

Now, network-to-host byte order conversion only occurs by default for two specific RTP types (both having a sample rate of 44100, which Auto-RX does not use), and the -b argument takes a parameter: -b 0 turns off network-to-host byte order conversion, while -b 1 turns it on.

Because of the change to the -b argument, it would be impractical for Auto-RX to support both behaviours. Since Auto-RX expects samples in host byte order, explicitly requesting that with -b 1 seems wise, even if it means dropping support for older versions of ka9q-radio.

If this change is adopted, we'll need to update the wiki to recommend commit 541c15849cbe59694770ca1b2bbad1835ad3667f of ka9q-radio. I think it's worth moving forward to this commit, since it includes several bug fixes:

• Fix RTL-SDR gain settings ka9q/ka9q-radio#63
• Don't discard calibrate setting ka9q/ka9q-radio#64
• Remove trailing comma from powers output, and don't override the locale ka9q/ka9q-radio#65