Update for heldItem in voxel-mine

Requires deathcap/voxel-mine@c7d759a3229abf09904b53f03e31a349cc63f819
Update to ProgrammerArt 1.1-dev with item textures
Add pickaxes, mines faster (for now: wooden 2x, diamond 10x) + cheats to acquire (press P or L)

Requires https://github.com/deathcap/voxel-mine/commit/72aaed6376e131914cefac90dd83026889a57222
and https://github.com/deathcap/voxel-registry/commit/a1e69742337aac36fc61429733adc5682eba7a84
Set tag on pickaxes, {damage:0}, to prevent stacking

Requires https://github.com/deathcap/itempile/commit/537befb2fda06475211c6d404d6e6b9558e48f6a