Script: adds Script.EMPTY constant
Script: use fromChunks internally for all Script templates
Transaction: remove unnecessary Buffer copy
Transaction: remove unnecessary clone
Script: parseChunks now uses bufferutils
Script: re-order functions to project order

Removes Script.parseChunks and merges it into Script.fromBuffer
Script: check hex not template result
Script: move all templates to templates.js
Address: fix consistent casing
Script: early exit in chunk.reduce
templates: rename to scripts
Script: remove clone