Remove lambdas from WinRawMouse.ProcessMouseEvents

Change WinRawMouse.ProcessMouseEvents to call code directly instead of using lambdas.  The lambdas caused memory allocations and were unneeded. 

Example of allocations that no longer occur with patched code:

![Profiling](https://f.cloud.github.com/assets/3211021/433618/b86e29f8-aedd-11e2-8c5a-cb3b6b071818.PNG)

As noted in [Commit 5b0db16a89b9648d04627ae60e9020dc7521b54a](https://github.com/andykorth/opentk/commit/5b0db16a89b9648d04627ae60e9020dc7521b54a)