Privacy enhancements to wallet network behavior

[xmr-karnal]

Based on a discussion ~1week ago on bitsharestalk.org, I'd like to propose the following:

• Allow selecting a wss:// endpoint per wallet, to help prevent the server from correlating requested balances (that map to account name) with the users' ip address.
• When switching between wallets, tear down the connection to the server; Add an option to re-establish the connection after about $selectable seconds.
• Implement SOCKS5 proxying support, possible HTTP as well, so that the client can further gain in privacy by hiding the originating ip address from the server.

[svk31]

This issue was moved to bitshares/bitshares-ui#57