-e Unity fails to generate proper VS2013 solution when there's umlauts in the path to the Unity project

-repro:
- have unity project in path with umlauts
- switch platform to "windows store"
- select "unity C# projects" checkbox
- build project
- open resulting VS solution in VS2013
-> VS cannot resolve paths due to broken umlauts in path

example error:
C:\Users\Unity Technologies\Desktop\testumläut\builds\testumläut\testumläut.csproj : error : The project file could not be loaded. Could not find a part of the path 'C:\Users\Unity Technologies\Desktop\testumläut\builds\testumläut\testumläut.csproj'. C:\Users\Unity Technologies\Desktop\testumläut\builds\testumläut\testumläut.csproj