Clojure API for Glowstone

Bukkit wrapper and

Create and handle Glowstone ServerConfig instances

Generally to configure Glowstone you edit YAML files, but that's not very
Clojure-y. This config munging below allows you to define config values as
inline EDN. The values in the config map that you provide to [[data-config]]
or [[server-config]] are keywords derived from the `ServerConfig$Key` enum,
see `(keys config-keys)`

(require '[lambdaisland.witchcraft.cursor :as c])

(-> (c/start)
    (c/draw)
    (c/material :red-glazed-terracotta)
    (c/steps 3)
    (c/rotate 2)
    (c/material :blue-glazed-terracotta)
    (c/steps 3)
    (c/rotate 2)
    (c/material :green-glazed-terracotta)
    (c/steps 3)
    (c/rotate 2)
    (c/material :yellow-glazed-terracotta)
    (c/steps 3)
    (c/build)
    )

Logo-like API for drawing blocks by using a walking metaphor.

This is a functional API, movements simply build up a list of block positions,
call [[build]] at the end to actually make them materialize in the game.

A cursor contains a current location (x/y/z), a
directions (:north, :north-east, :east, etc.), and a current building
material, e.g :lapis-block (see [[lambdaisland.witchcraft.bukkit/materials]]).

It also contains a drawing flag `:draw?` and a list of blocks `:blocks`. When
drawing is on, then any step will add a block to the list. [[build]] creates
blocks in the world based on this, and resets the list.

Call [[start]] to get an initial cursor, this will return a cursor that is one
step ahead of the player (so what you draw is in sight), facing away from the
player.

```
(require '[lambdaisland.witchcraft.cursor :as c])

(-> (c/start)
    (c/draw)
    (c/material :red-glazed-terracotta)
    (c/steps 3)
    (c/rotate 2)
    (c/material :blue-glazed-terracotta)
    (c/steps 3)
    (c/rotate 2)
    (c/material :green-glazed-terracotta)
    (c/steps 3)
    (c/rotate 2)
    (c/material :yellow-glazed-terracotta)
    (c/steps 3)
    (c/build)
    )
```