VM improvements, tests + bugfixes (#61)

* changed vm commands to match more of the standard

* fixed Uint16 jmp bug in VM

* moved test to vm + fixed numnotequal bug

* fixed broken tests

* moved compiler tests to vm tests

* added basic for support + inc and dec stmts

* bumped version

pkg/vm/test/binary_expr_test.go

@@ -0,0 +1,116 @@
+package vm_test
+
+import "math/big"
+
+var binaryExprTestCases = []testCase{
+	{
+		"simple add",
+		`
+		package testcase
+		func Main() int {
+			x := 2 + 2
+			return x
+		}
+		`,
+		big.NewInt(4),
+	},
+	{
+		"simple sub",
+		`
+		package testcase
+		func Main() int {
+			x := 2 - 2
+			return x
+		}
+		`,
+		big.NewInt(0),
+	},
+	{
+		"simple div",
+		`
+		package testcase
+		func Main() int {
+			x := 2 / 2
+			return x
+		}
+		`,
+		big.NewInt(1),
+	},
+	{
+		"simple mul",
+		`
+		package testcase
+		func Main() int {
+			x := 4 * 2
+			return x
+		}
+		`,
+		big.NewInt(8),
+	},
+	{
+		"simple binary expr in return",
+		`
+		package testcase
+		func Main() int {
+			x := 2
+			return 2 + x
+		}
+		`,
+		big.NewInt(4),
+	},
+	{
+		"complex binary expr",
+		`
+		package testcase
+		func Main() int {
+			x := 4
+			y := 8
+			z := x + 2 + 2 - 8
+			return y * z
+		}
+		`,
+		big.NewInt(0),
+	},
+	{
+		"compare equal strings",
+		`
+		package testcase
+		func Main() int {
+			str := "a string"
+			if str == "another string" {
+				return 1
+			}
+			return 0
+		}
+		`,
+		big.NewInt(0),
+	},
+	{
+		"compare equal ints",
+		`
+		package testcase
+		func Main() int {
+			x := 10
+			if x == 10 {
+				return 1
+			}
+			return 0
+		}
+		`,
+		big.NewInt(1),
+	},
+	{
+		"compare not equal ints",
+		`
+		package testcase
+		func Main() int {
+			x := 10
+			if x != 10 {
+				return 1
+			}
+			return 0
+		}
+		`,
+		big.NewInt(0),
+	},
+}