Store CX attachments in the database instead of filesystem

Overriding the original attachmentService with a new DatabaseAttachmentServiceImpl.

Added a new column to KRNS_ATT_T and mapped it to DatabaseAttachment.

fixes rSmart/issues#244
That's going to be difficult to get the formatting just right since I copy pasted and in my editor (due to use of tabs) I don't see the differences. Even vim is formatting it correctly. As far as readability goes, it looks pretty obvious that block a was replaced with block b.