Add handler to node.js server for vwf /admin/chrome requests

fixes #2891
Have HandleAdminChrome return an empty string if html overlay does not exist

refs #2891
Merge pull request #48 from virtual-world-framework/branch/node.js-chrome-requests

Branch/node.js chrome requests
Pull out repeated code into a parseSocketUrl function

fixes #2893
Makes the counter that the duck rotation is based off of a property
so that is is properly synched across multiple clients.

References #2805.
Created a socketManager variable to hold what is returned from sio.listen(..)

We had been reusing the sio variable for two different types of object.  I think that would have led to confusion.
refs #2893
Merge pull request #51 from virtual-world-framework/branch/node.js-refactor

Created a socketManager variable to hold what is returned from sio.liste...
Enable running test files directly using ruby without rake
Merge branch 'development' into branch/persistence-listsaves