Bug 2176 (1/5): database update: adding message_queue table and tables to hold patron...

Bug 2176 (1/5): database update: adding message_queue table and tables to hold patron messaging preferences

Updates to kohastructure.sql and updatedatabase.pl:
- add new message_queue table
- add message_transport_types table
- add message_attributes table
- add message_transports table
- add borrower_message_preferences table
- add borrower_message_transport_preferences table
- adding EnhancedMessagingPreferenes to sysprefs SQL.

Added column to borrowers table to hold SMS Alert Number.
Added some more sample notices (letters) that will be sent for patron alerts
added some sample SQL to configure messaging.

Signed-off-by: Joshua Ferraro <jmf@liblime.com>