[conformal/btcscript] c33bd1: Add a new func CalcMultiSigStats.

[Dave Collins]

  Branch: refs/heads/master
  Home:   https://github.com/conformal/btcscript
  Commit: c33bd15df2cce3edfa021fbe67b4e56192d180f5
      
https://github.com/conformal/btcscript/commit/c33bd15df2cce3edfa021fbe67b4e56192d180f5
  Author: Dave Collins <da...@conformal.com>
  Date:   2013-11-14 (Thu, 14 Nov 2013)

  Changed paths:
    M script.go

  Log Message:
  -----------
  Add a new func CalcMultiSigStats.

This commit adds a new function to extract the number of pulic keys and
number of signatures from a multi-signature script.

ok @owainga