add physics overrides to armor

[Bremaweb]

adds physics overrides to groups, for example in register_tool:

groups = {armor_feet=10, armor_heal=0, armor_use=100, physics_jump=.58},

this pull request adds physics_jump, physics_speed, and physics_gravity to groups

[stujones11]

I like the idea of adding physics, however, I am a little concerned about this implementation. Not had a chance to test this yet but I believe the elements table was added by BlockMen for HUD integration.

Edit: my mistake, i thought you had removed the elements table, I see now that you removed has_physics. I will test this asap but I may have to figure a way around the 10 second delay. Not sure I like that but then you are the one running a server.

[stujones11]

It would also be nice to actually use this feature in the default armor since most people would not know how to create custom armor. On the other hand, we should keep these quite subtle as it is not difficult for other mods to provide custom armor items.

[Bremaweb]

Well the 10 second delay worked in singleplayer but when I put it on my server the physics changes still weren't applied when they logged on so that might as well be put back to 0. I'm not sure at what point the client applies any changes to the physics. There needs to be a minetest.registeron function in the api that would be called when the client is fully connected, everything is downloaded, and they are in the game ready to play.

Adding custom armor from another mod is super easy. I have a mod just for my server that creates two custom armor pieces, Jump Boots, and Speed Leggings. So I've been running this for several months, but just updated to the latest of 3d_armor and decided to submit this pull request.

[stujones11]

Ok, put the delay back to either 0 or 1 for now and I will merge this. We can work on the other problem as a separate issue. I would make the change myself but I am still learning this git stuff and would surely mess it up,

Thanks.

[Bremaweb]

Ok, change the delay to 1.