Add a 'player edits book' event

an event for when a player edits/signs book, see added meta for infos.
Also fix a few typos
Add book script meta+add 'signed' option to books

use 'signed: false' to make the item a book_and_quill instead of a
written_book. Thus reducing need for item script / book script combos.
Debug recording efficiency

+ some code commenting.
Update to Bukkit 1.7, Citizens 2.0.11

Everything seems to work, except the fishing trait.
Catch startup error

Finally found the bugger. I'm fairly sure this one can be blamed on
Bukkit... just catch it so it doesn't break on startup.
Catch Bukkit-induced error in 1.7 - placeblock

Event is fired incorrectly every time... ignore it for now until Bukkit
fixes that.
Merge pull request #541 from mcmonkey4eva/master

I could write a book about this pull request - MC 1.7 update as well!