Upgrade to Nest 1.0.1

Created for issue #2 

I've made the following enhancements:
1. Upgrade to Nest 1.0.1
2. upgrade to json.net 6.0.4
3. add ability to specify the default index within the connection string (legacy way of specifying within the elmah config still supported).
4. new unit tests for new functionality
5. let ES define the ID, it will be a bit less consistent but it will be considerably faster
My thinking on that is then everything is contained in the connection string.  If you think about a SQL Server connection string, it specifies the server name as well as the instance name.  This also allows for easier web.config.transforms which people will presumably have already for the connection strings (or they will have a tool like Octopus Deploy that does something similar).