Replace current custom ProxyControl/Proxy implementation by LittleProxy

[asfimport]

@pmouawad (Bug 60821):
Hello,
Our current implementation of Proxy is very tightly coupled to HTTP 1.0/1.1 protocol and not made to be easily extended.

What do you think of switching to LittleProxy

• https://github.com/adamfisk/LittleProxy

Which has by the way started some work on HTTP/2 support:

• Logistics of HTTP/2 and Netty 4.1 adamfisk/LittleProxy#229

OS: All

Blocks:

• Create a new Recorder less tightly coupled with underlying recorded protocol #4189