txscript: Optimize typeOfScript pay-to-pubkey-hash.
txscript: Optimize typeOfScript pay-to-pubkey-hash.

This continues the process of converting the typeOfScript function to
use a combination of raw script analysis and the new tokenizer instead
of the far less efficient parsed opcodes.

In particular, it converts the detection of pay-to-pubkey-hash scripts
to use raw script analysis.

ltcsuite/ltcd,tb00/btcd,btcsuite/btcd,btcsuite/btcd,davecgh/btcd,tb00/btcd,ltcsuite/ltcd,davecgh/btcd