Solved minor compatiblity issues with Visual Studio 2014 CTP.

Solved a whole bunch of Unsigned/Signed miss-matches.
Explicitly defined a whole bunch of floating points, because VS is anal about that.
Explicitly defined a whole bunch of type conversions where appropriate.

I was hoping this would also get the November 2013 C++ Compiler CTP to work, but it crashes working with the  current version of SOL.
Compatibility with Visual studio 2013 is also possible but this involves reverting the version of SOL to 1.1.0 which introduces a problem when marshaling pointers.
This can be bypassed by casting pointers to size_t's before declaring the lua function lambda.

The whole solution is kinda intrusive compared to the minor 2014 CTP changes, so i suggest we just exclusively support the 2014 CTP instead.

I tried fixing the compiler bug in sol/traits.hpp in various ways, but it seems impossible to regain the actual functionality without crashing the compiler or passing a template type to a template which isn't allowed by the compiler.
Its a stupid solution, but it gets it to compile and doesn't cause any problems, and isn't very likely to do so in the future.