Fixed errors on data loading when MySQL is being used.
Changed messages system to use simple file as default. If you want to use advanced translation just rename "advanced-messages.yml" to "messages.yml".
There is a bug/feature in 1.8 which adds '§0' at the end of every line in books generated
by plugins. This breaks the conditions/events based on books with more than one line of text.
The detailed instruction on how to work it around is in "Other important stuff" chapter, in
the part about items.