added dialog for mesh writer options
adjusted vtu-interface to support binary and append flags
added support for mesh name in VtkMeshConverter
added dialogue to select vtk data writer options
adjusted mesh view to use new dialogue
removed comments and unnecessary code
formatting
correct handling of empty path
Fixed VtuInterface ascii writing.

Save mesh dialog compression availability check.
added encode flag for appended data
removed void param
Merge pull request #522 from rinkk/MeshWriterConfig

Mesh writer config. Extend VtuInterface.