Guide-API

Tombenpotter: Added lots of javadocs
Tombenpotter: Fix the items not being inside the grid
tterrag1098: Fix book serialization failing, fix example json file
tterrag1098: Remove debug code
Tombenpotter: Half-working page saving.
Tombenpotter: I don't know why this is even private
Tombenpotter: 3 / 4 working
Tombenpotter: So I need packets. Now 0% working
Tombenpotter: Now 100% working! Thanks to @hilburn and @tterrag1098
Tombenpotter: Moved the gsonBuilder to GuideRegistry so that other people can access it
Tombenpotter: Disable Test Book for new release