dispose the database cursor on db_trans() finish
format comment
do not import unused modules
fix copyright year
porting to bottle 0.12
update waitress version
break long lines
fix trailing whitespaces per pylint suggestion
change config variable to uppercase
better variable name
do not use assert to validade input data
fix months calculation in time delta
fix saving last status on database
better variable name
move database schema migration to a separate class
add tests for database schema migration