Moved BabylonJS.csproj to Tools/BuildOurOwnBabylonJS/BabylonJS and fixed Julien's pull-request

Once I moved BabylonJS.csproj to Tools/BuildOurOwnBabylonJS/BabylonJS (see https://github.com/BabylonJS/Babylon.js/pull/125), I noticed that ourOwnBabylon.js was not valid anymore so I fixed Julien's pull-request.

There is no error anymore but the Train Demo behaves strangely. The camera is like leaving away.

I think this tool can actually be really helpful to test any pull-request against all demos.