Code tidy, add .luacheckrc

Improve callbacks

.luacheckrc

@@ -0,0 +1,50 @@
+allow_defined_top = true
+
+read_globals = {
+	"ItemStack",
+	"vector",
+	"VoxelArea",
+	"VoxelManip",
+	"PseudoRandom",
+
+	string = {fields = {"split"}},
+	table  = {fields = {"copy"}},
+	math   = {fields = {"hypot"}},
+	os     = {fields = {"time"}},
+}
+
+globals = {
+	"minetest",
+}
+
+files["shooter/init.lua"] = {
+	globals = {"shooter"}
+}
+
+files["shooter_crossbow/init.lua"] = {
+	globals = {"shooter", "SHOOTER_ARROW_TOOL_CAPS", "dye"}
+}
+
+files["shooter_flaregun/init.lua"] = {
+	globals = {"shooter"}
+}
+
+files["shooter_grenade/init.lua"] = {
+	globals = {"shooter"}
+}
+
+files["shooter_guns/init.lua"] = {
+	globals = {"shooter"}
+}
+
+files["shooter_hook/init.lua"] = {
+	globals = {"shooter"}
+}
+
+files["shooter_rocket/init.lua"] = {
+	globals = {"shooter"}
+}
+
+files["shooter_turret/init.lua"] = {
+	globals = {"shooter", "player_api"}
+}