Add some ranged weapons

[fluxionary]

This is necessary before the introduction of hostile mobs (#94)

[luk3yx]

Mod candidates (that I know of):

• rangedweapons: This would probably need a rewrite, it uses deprecated API functions and most of the code is copy+pasted.
• projectiles: This only adds two guns, however has a nice API that would make adding more guns relatively trivial.

[niwla23]

gunslinger has a cool api too

[thomasrudin]

the rangedweapons mod is a mess, most of the bullets ignore solid walls and go through everything...

[fluxionary]

It's sounding like I'll probably have to cobble this together from several other mods to get what we want.

Some feedback from users:

1. Many players don't think guns fit the server, so probably won't go gun-heavy, if I use any.
2. "Magic" stuff is very much out
3. Things that shoot arrows (e.g. from https://github.com/minetest-mods/castle_weapons ) are a good fit
4. Thrown weapons are good, even down to thrown rocks
5. I personally like the idea of a boomerang, but I'm not super keen on writing that from scratch..
6. Maybe a heat-ray based on the terumet mod, that lights enemies on fire? (convert a HEAT laser; power w/ heat)

[fluxionary]

7. Use the fire flower from moreplants to throw fireballs like mario

[fluxionary]

So we currently actually have 2 ranged weapons that sort of got introduced w/out much thought - snowballs, and items flung from the hook mod's slingshot. These are actually probably both good things, but they need a bit more work.