Added type check for console.log to prevent IE8+modernizr issues

nv.d3.js

@@ -35,10 +35,13 @@ if (nv.dev) {
 //  Public Core NV functions
 
 // Logs all arguments, and returns the last so you can test things in place
+// Note: in IE8 console.log is an object not a function, and if modernizr is used
+// then calling Function.prototype.bind with with anything other than a function
+// causes a TypeError to be thrown.
 nv.log = function() {
   if (nv.dev && console.log && console.log.apply)
     console.log.apply(console, arguments)
-  else if (nv.dev && console.log && Function.prototype.bind) {
+  else if (nv.dev && typeof console.log == "function" && Function.prototype.bind) {
     var log = Function.prototype.bind.call(console.log, console);
     log.apply(console, arguments);
   }

src/core.js

@@ -34,10 +34,13 @@ if (nv.dev) {
 //  Public Core NV functions
 
 // Logs all arguments, and returns the last so you can test things in place
+// Note: in IE8 console.log is an object not a function, and if modernizr is used
+// then calling Function.prototype.bind with with anything other than a function
+// causes a TypeError to be thrown.
 nv.log = function() {
   if (nv.dev && console.log && console.log.apply)
     console.log.apply(console, arguments)
-  else if (nv.dev && console.log && Function.prototype.bind) {
+  else if (nv.dev && typeof console.log == "function" && Function.prototype.bind) {
     var log = Function.prototype.bind.call(console.log, console);
     log.apply(console, arguments);
   }