Improvements and fixes

• Improved error message sent from the nShift Alert system when an EDI transmit fails.
• Added support for legaldays="0" for Sunday.
• Fixed error message for GetDropPoint request.
• Fixed issue with multi-page PDF labels breaking when using overlays.
• Fixed issue with carrier specific report being printed in portrait mode.
• Fixed issues related to virtual containers.
• Fixed issue with detail lines missing on custom documents.
• Performance and stability improvements.
• Various technical fixes and refactoring.