[btcsuite/btcwallet] b1500b: Print version string at startup.

[John C. Vernaleo]

  Branch: refs/heads/master
  Home:   https://github.com/btcsuite/btcwallet
  Commit: b1500ba02b93255bb506c17af12ac30ffc8cefb3
      
https://github.com/btcsuite/btcwallet/commit/b1500ba02b93255bb506c17af12ac30ffc8cefb3
  Author: John C. Vernaleo <j...@netpurgatory.com>
  Date:   2016-03-21 (Mon, 21 Mar 2016)

  Changed paths:
    M btcwallet.go

  Log Message:
  -----------
  Print version string at startup.

This makes btcwallet match btcd's behavior.

Initially pointed out in:
decred/dcrwallet#125