Removes first sentences from error messages in lib/mshoplib/src/* , which described the domain the error occured in.
Removes full stops at end of error messages in lib/mshoplib/src/* containing only one sentence
Improves a few error messages
Removes full stops at end of error messages in lib/mshoplib/src/* in some more files
Fixes minor errors in the code for successful testing with 'phing test'
Updates German translation file and POT file, adds English translation file with empty msgstr