--bind-to check prioritized. Use iface address instead of loopback if available.

This PR does the following:

- `--bind-to` command line option is used to solve the multi-homed node issue. It is is processed before other arguments and `LPROC.bind_addr` is set the ip-address suggested on the command line (if present), else it is set to whatever is returned by `getipaddr()`. 

- detects which of the processes are on the localhost and only uses the loopback address to connect to them - this is resilient across system sleep/wake cycles.

- The machine line in `--machinefile` file format (as also `addprocs(machines::Vector)`), is now of the form `[user@]host[:port] [bind_addr]`. i.e., it supports an optional `bind_addr` field that is passed as a command line argument to the started workers.

Closes https://github.com/JuliaLang/julia/issues/5995