[PATCH] rtl_fm null squelch

Hi all, I've created a simple little change for rtl_fm which outputs values of 0 (instead of nothing) when the output is squelched. Use the command option "-E nullsquelch" to enable. This is useful when live streaming output to icecast or similar which requires a constant stream of data (such as http://rtl-sdr.com/forum/viewtopic.php?f=7&t=141 or http://www.windytan.com/2013/07/squelch-it-out.html). Hopefully someone can merge this into the git repo, otherwise just patch and build yourself. Cheers, Wilson -- *Wilson Waters* | Software Engineer *Alintech* e: wilson.waters@alintech.com.au w: www.alintech.com.au