Add functionality for inspecting arbitrary past calls

This made it much easier to debug multiple calls while developing this
patch.

ospec/README.md

@@ -111,6 +111,7 @@ o.spec("call()", function() {
 
 		o(spy.callCount).equals(1)
 		o(spy.args[0]).equals(1)
+		o(spy.calls[0]).deepEquals([1])
 	})
 })
 ```

ospec/ospec.js

@@ -49,6 +49,7 @@ else window.o = m()
 		var spy = function() {
 			spy.this = this
 			spy.args = [].slice.call(arguments)
+			spy.calls.push({this: this, args: spy.args})
 			spy.callCount++
 
 			if (fn) return fn.apply(this, arguments)
@@ -59,6 +60,7 @@ else window.o = m()
 				name: {value: fn.name}
 			})
 		spy.args = []
+		spy.calls = []
 		spy.callCount = 0
 		return spy
 	}

ospec/tests/test-ospec.js

@@ -206,6 +206,8 @@ o.spec("ospec", function() {
 			o(spy.callCount).equals(1)
 			o(spy.args.length).equals(1)
 			o(spy.args[0]).equals(1)
+			o(spy.calls.length).equals(1)
+			o(spy.calls[0]).deepEquals({this: undefined, args: [1]})
 		})
 		o("spy wrapping", function() {
 			var spy = o.spy(function view(vnode){
@@ -223,6 +225,8 @@ o.spec("ospec", function() {
 			o(spy.callCount).equals(1)
 			o(spy.args.length).equals(1)
 			o(spy.args[0]).deepEquals({children: children})
+			o(spy.calls.length).equals(1)
+			o(spy.calls[0]).deepEquals({this: state, args: [{children: children}]})
 			o(state).deepEquals({drawn: true})
 			o(output).deepEquals({tag: "div", children: children})
 		})
@@ -461,7 +465,7 @@ o.spec("ospec", function() {
 			oo.spec("nested 3", function () {
 				oo("", function() {
 					oo(true).equals(true)
-	
+
 					return {then: function() {}}
 				})
 			})
@@ -490,10 +494,10 @@ o.spec("ospec", function() {
 						o(diff >= 50).equals(true)
 						o(diff < 80).equals(true)
 					})
-		
+
 					oo("", function() {
 						oo(true).equals(true)
-		
+
 						return {then: function() {}}
 					})
 				})