Update frmSurface.vb

Bug fix
Update XMLSerializer.vb

Fixed serialization of Double and Single data types.
Workaround for CAPE-OPEN terminate call error during flowsheet close event;
Fix for zeroing mass and mole flow through CAPE-OPEN calls;
Workaround for Gibbs PT-Flash algorithm reaching maximum number of iterations (which happens on single phase regions);
Updated Cudafy.NET.dll to v1.26, compiling CUDA code with CUDA SDK 5.5 and Visual C++ 2012 Express.
Added a new "Stream Flow Spec" operation mode for the Splitter Unit Operation.
Fixes and enhancements to three-phase flash algorithms.
New three-phase flash algorithm, Nested Loops (VLLE), based on the following paper: http://dx.doi.org/10.1016/j.fluid.2005.11.011
Merge pull request #3 from DanWBR/master

Merge changes from DanWBR/dwsim3