Merge branch 'development' of https://github.com/sshipway/mcdungeon into sshipway-development
Merge branch 'sshipway-development' into development
Fixes a crash in data chests:

* non-book items appear.
* Print additonal info about chest, item, and title (if it exists)
Fixes Issue #230
Adds Sea Lanterns to pymclevel
Roll back last pymclevel change.
Finishing touches to shops. Issue #95

- Add final shop and tweaks to existing
- Add to all configs. Slightly higher weight to make it a little easier
to find the shop variants
Switch pymclevel submodule to mcdungeon fork.
Update pymclevel.
Updates to pymclevel for lighting issues.
Fix build script for changing submodule URLs.
Adds overviewer_icons is build script.
Use HTTPS and not SSH for pymclevel submodule.
Update for 1.8 book tags. Issue #229
Escape quotes in book tags. Issue #229
Fix data values for:

Double Red Sandstone Slab
Red Sandstone Slab

Issue #226
Pre-merge commit
Merge remote-tracking branch 'upstream/development' into development

Conflicts:
	features.py
	mcdungeon.py
	utils.py
Fix treasure hunt bugs

- Unburied cache chest
- missing lighting handler
- invalid directions between steps
- missing cottage fireplace back