Change some recipes; Add seed level to tooltip; show player level in gui; update chat to use core prefix (see lang file); Removed backward compat xp save/load code, just created problems
Command update and couple fixes

Made ChowTimeCommand extend CommandBase rather than implement ICommand so it is an op command and more fleshed out.
Fix xp stuff so 20 is new level, not 21, etc.
Make lang file a little better.
Fix higher tier crops not giving more xp.