Use VisualStudio user files to automatically configure debug/release

This commit is based on the contribution kindly provided by Florian Jung.
Configure a .vcxproj.user file for each executable either created via the
mitkMacroCreateExecutable or by mitkFunctionCreateBlueBerryApplication.
Additionally a new cmake function is provided to do the configuration
mitkFunctionConfigureVisualStudioUserProjectFile.
Batch files are still generated for debugging purposes and for directly
runnning the executables without using visual studio.