[btcsuite/btcscript] 8e6abd: Make several of the reg tests more consistent.

[Dave Collins]

  Branch: refs/heads/master
  Home:   https://github.com/btcsuite/btcscript
  Commit: 8e6abdb1257ccef62e5d05e4bcd64f51f8745082
      
https://github.com/btcsuite/btcscript/commit/8e6abdb1257ccef62e5d05e4bcd64f51f8745082
  Author: Dave Collins <da...@conformal.com>
  Date:   2015-01-29 (Thu, 29 Jan 2015)

  Changed paths:
    M opcode_test.go
    M script_test.go
    M stack_test.go

  Log Message:
  -----------
  Make several of the reg tests more consistent.

This commit modifies various regression tests to make them more consistent
with other tests throughout the code base.

Also, it allows of all the tests to run in parallel.