Fix undefined behavior in setting neuron params.

Calling the RNG inside the call to Neuron#setParams exploits undefined
behavior in C++. These calls may be ordered as the compiler sees fit.
Change makes setParams more deterministic.
Adding VS2012 Project Files

The ".vxproj" is for Visual Studio 2012. I've only tested building
Debug, OMP Debug (OpenMP) versions.
Updates to VS2012 Project and IOCP

IOCP_Sim.cpp is excluded from builds (which then excludes
SingleThreadedSim). Might want to "tidy up" this method of
implementation since having two classes the same name isn't really
kosher.
These are the changes I've made to 'master' in order to
get a successful Windows compilation (using Visual
Studio 2012). Please feel free to let me know if I've broken
anything, and I'll try to fix the issue. Alternatively, just
back out my changes).
Fix bgtypes.h
Changes for compiling on linux