[Bleeding] Add 1.7 setworldspawn and setidletimeout commands. Addresses BUKKIT-4932
Modify give command to support 1.7 features. Fixes BUKKIT-5286

Necessary additions include an interface to add internal value conversions
that are inappropriate for proper API design. This acts as a substitute
for properly formed, user-friendly commands in an effort to maintain
relatively vanilla behavior.