[conformal/btcscript] 126991: Make opcode disasm names match reference impl.

[Dave Collins]

  Branch: refs/heads/master
  Home:   https://github.com/conformal/btcscript
  Commit: 126991b60bc6ee1ef0196cd96e40f04058144229
      
https://github.com/conformal/btcscript/commit/126991b60bc6ee1ef0196cd96e40f04058144229
  Author: Dave Collins <da...@conformal.com>
  Date:   2014-01-07 (Tue, 07 Jan 2014)

  Changed paths:
    M opcode.go
    M opcode_test.go
    M test_coverage.txt

  Log Message:
  -----------
  Make opcode disasm names match reference impl.

This commit modifies the names of opcdoes shown in the oneline script
disassembly to match the reference implementation.  In particular
OP_1NEGATE, and OP_0 through OP_16 are changed to the raw numbers
they represent when doing oneline disassembly.  When doing full
disassembly, the full opcode names are still shown.

ok @owainga.