Node 0.11.13

This is a first hack at getting Edge to run with the latest (unstable) node.js - 0.11.13.   Mainly so I can play with the co library.  I've only had a couple of days to go over this - so I'm sure that some of my changes could be replaced with something more concise.  Don't have any info on performance issues, and since the changes in Persistent class means that a Local<Value> handle needs to be created for each call, it's possible the memory leak referenced in https://github.com/tjanczuk/edge/issues/125 is back.  

There have been quite a few changes in v8: 

* the addition of Isolate, 
* changes to String::New and String::NewSymbol.  
* The use of EscapeableHandleScope::Escape instead of HandleScope::Close
* Global object now obtained via the Isolate, 
* Exceptions thrown via the Isolate, 
* New generally requires an Isolate
* Persistent now does not inherit from Object; need for CopyablePersistentTraits
* Arguments replaced with FunctionCallbackInfo<Value>

I've only made changes only made to the dotnet and common src files;  added 0.11.13 version tags in edge.js.

Hope it helps -- if it's not a timely update branch, feel free to ignore :-)

Regards
Tim Findlow