Add V1 fallback mode to the proxy

[nyonson]

Adding the flag --v1-fallback to enable falling back to the V1 protocol if the remote doesn't support V2.

Deprecates the old v1 binary of the proxy app. This was only used for our own tests and doesn't serve much of a purpose now. The logic was folded into the remaining proxy app.

Closes #27

[nyonson]

@Kixunil does configure_me support bool flags where you don't have to give an argument? For example, I am passing --v1-fallback=true, but would be nice to just set --v1-fallback.

[rustaceanrob]

ACK 49a4d98

[rustaceanrob]

Let's get this is in and we can improve the CLI arg if possible later