Major bug fix to enchanted books

Major bug fix to enchanted books - now writes the correct tag. Not sure
how this change never got checked in.
Whitespace.
Small fix for relocating the RuinedFane.
Alignment tweaks to RuinedFane. (needs more)
Adds 3 multi-spawners

Adds 3 multi-spawners for issue #108 These spawn the normal mob 80% of
the time and a 'powered' version 20% of the time.

multi_creeper - chance of charged creeper
multi_skeleon - chance of wither skeleton
multi_zombie - chance of zombie with speed and strength effect
Add full support for enchanted books. Closes #100
Make READMEs README.txt on standalone systems.

Issue #125
Issue #126
Fixed my dumb fix for #125 and #126.
Simplified setting the exit portal.
Adds exit portal for RuinedFane.
Improved ruin function. Adds ruin to RuinedFane. #123
Fixed bug with Pyramid portal placement.
Added wooden doors to structures to help avoid villages.
CHANGELOG updates.
Configurable secret rooms

- Makes creating new rooms easier. Issues #102 #89
- Moved cobweb code to a dungeon member function.
- Recreated study, alchemy lab, and sepulchre.
- Closes #118
Fix book processing

Fix calls to lower function
Fix skeleton spawner weapons. Closes #127
Add option to generate two max tier chests in treasure rooms

Add option to generate two max tier chests in treasure rooms.

Switched on in hard_mode.
Document included spawner NBTs. Closes #124
Adds helper functions for placing entites. Issue #90

Random chance of a villager priest in RuinedFane.
A horrific painting above the alter in RuinedFane.
SecretStudy contains a clock on the wall.