Adds missing sprintf() in some error messages
Fixes minor mistake in error message
Improves error messages: unifies messages for same error types and adds more information to some messages
Fixes sprintf() where variables were used for message string. Replaces variables with string, so that gettext can grab the msgid for translation template file.
Improves error messages, which used variables instead of message string (fixed in last commit): unifies messages for same error types and adds more information to some messages.
Fixes minor mistakes in message ids in lib/mshoplib/src/MShop/Context/Item/Default.php
Adds German translations for error messages, which used variables instead of message strings, in lib/mshoplib/src
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
Merge pull request #127 from dahoffmann/2013-03-13_GermanTranslationErrorMessages

Improves German translation and streamlines error messages