Servicestack templates updated

- Upated Servicestack icon. 
- Added V4 templates  too. 

So, now there are 8 templates.

 - V3 self host
-V3 asp.net host
V3 self host with Razor view engine
V3 asp.net host with Razor view engine
V4 self host
V4 asp.net host
V4 self host with Razor view engine
V4 asp.net host with Razor view engine

Tested on VS2012 and VS2013