minor: remove the bit left in the readme which said .net 3.5 framework was required

README.md

@@ -17,8 +17,6 @@ need to build OpenSim before running it.
 
 # Running OpenSim on Windows
 
-You will need .NET Framework 3.5 installed to run OpenSimulator.
-
 You will need .NET 4.0 installed to run OpenSimulator.
 
 We recommend that you run OpenSim from a command prompt on Windows in order