[conformal/btcd] ae89f7: Expand btcctl RPC cert path to from config file.

[Dave Collins]

  Branch: refs/heads/master
  Home:   https://github.com/conformal/btcd
  Commit: ae89f7aa824c438ecde450a2db87b64f40dd81dd
      
https://github.com/conformal/btcd/commit/ae89f7aa824c438ecde450a2db87b64f40dd81dd
  Author: Dave Collins <da...@conformal.com>
  Date:   2014-03-19 (Wed, 19 Mar 2014)

  Changed paths:
    M util/btcctl/config.go

  Log Message:
  -----------
  Expand btcctl RPC cert path to from config file.

This commit allows paths in the btcctl config file to use environment
variables and ~ as a shortcut for the home directory.

Closes #113.