Remove the useless file num_digits.
Rename error/warning_packet to error/warning. Packet is implicit.
Modify the logging to elegantly trace function calls (using the macro BOOST_CURRENT_FUNCTION. Also delete the useless handle_request method in connection.
Add OTL header (database access library).
Rename the database directory to umcd instead of campaign_server.
Move the database schema in the data repository.
Change smallint to int.
Add unixodbc-dev to be installed in travis file.