change env.state to env.engine
bring op_add_sibling up to speed
change ScriptInput signature scheme
add/reorder some opcodes
remove LDFLAGS from fmt target
'rest' opcodes no longer move dptr
uncomment interpreter tests
update script opcodes
uncomment op_verify and TestVerify
change debug info
sign the whole ScriptInput
comment out broken code
Merge pull request #191 from lukechampine/reorg

restore scripting functionality