Reorganized pclasses and tweaked sprint bar

- Tweaked sprint bar in order to change its maximum value according to the one defined for each player
 - Reorganized pclasses into multiple files (api, init, one for each class). Next thing to do : document/simplify api

mods/pclasses/hunter.lua

@@ -0,0 +1,28 @@
+------------------
+-- Hunter class --
+------------------
+
+--
+-- See https://github.com/Ombridride/minetest-minetestforfun-server/issues/114
+--
+
+pclasses.api.register_class("hunter", {
+	determination = function(player)
+		return pclasses.api.util.does_wear_full_armor(player:get_player_name(), "reinforcedleather", true)
+			or pclasses.api.util.does_wear_full_armor(player:get_player_name(), "hardenedleather", true)
+	end,
+	on_assigned = function(pname)
+		minetest.chat_send_player(pname, "You are now a hunter")
+		minetest.sound_play("pclasses_full_hunter")
+		local reinforced = pclasses.api.util.does_wear_full_armor(pname, "reinforcedleather", true)
+		if reinforced then
+			sprint.increase_maxstamina(pname, 20)
+		else
+			sprint.increase_maxstamina(pname, 10)
+		end
+		minetest.log("action", "[PClasses] Player " .. pname .. " become a hunter")
+	end,
+	on_unassigned = function(pname)
+		sprint.set_default_maxstamina(pname)
+	end,
+})