trying to fix ScriptInterpreter
add script_interpreter
refactors and fixes for script interpreter
adding some signature methods for script interpreting
make creation methods class methods
Pubkey -> PublicKey
pass some more tests
trying to fix OP_CHECKSIG script evaluation
import Sighash
some more passing tests
fix some more tests
all script_valid tests passing!
generalize script tests
add Script#checkMinimalPush tests
fix all script validation tests, yay!
remove console.logs
style change to BufferUtil
script interpreting working
fix post-rebase confilcts
address review comments