Adding throttle function accessible with -H.

The minimum resolution is 1 Kib/s.

Can be used to simulate low performance input.
Adding max input TCP packet size option.

Can be used to test the performance with different packet sizes at the maximum or simulated maximum input rate.
Disabling sigint handler so that a rtmpdump job isn't terminated together with the parent shell when the parent shell receive sigint.

Disabling handling the other signals for faster exit.
Merge remote-tracking branch 'remotes/john-peterson/custom'

Conflicts:
	rtmpdump.c