GDM-200: don't hang on shapefile upload with problem reading zip
GDM-200: don't fail shp.zip upload on wrong file
GDM-200: use file separator in stead of "/"
Merge pull request #13 from geomajas/GDM-200_shpUpload_dontFailOnIncorrectZipFile

Gdm 200 shp upload dont fail on incorrect zip file