SIGNEXTEND opcode.
Add VMTRACE to user defined vm test
VMTRACE for internal calls
Interpret the second argument as byte number, not bit number.
use ETHEREUM_TEST_PATH in all tests
bugfix
Merge pull request #1 from chriseth/signextend

Implementation of SIGNEXTEND opcode
Merge remote-tracking branch 'origin/newTests' into newTests
Merge remote-tracking branch 'upstream/develop' into newTests

Conflicts:
	libevm/VM.h
	libevmface/Instruction.h
	test/vm.cpp
Merge remote-tracking branch 'upstream/develop' into newTests

Conflicts:
	test/vm.cpp
	test/vm.h
Added tests for SIGNEXTEND and BNOT
Fixed storage output in VMTRACE for vm tests
merge
Merge pull request #434 from CJentzsch/vmtraceBugFix

Vmtrace bug fix