add luacheck, add github action for luacheck, fix luacheck warnings, remove depreciated files

.github/workflows/luacheck.yml

@@ -0,0 +1,18 @@
+
+name: luacheck
+
+on: [push, pull_request]
+
+jobs:
+  build:
+
+    runs-on: ubuntu-latest
+
+    steps:
+    - uses: actions/checkout@v1
+    - name: apt
+      run: sudo apt-get install -y luarocks
+    - name: luacheck install
+      run: luarocks install --local luacheck
+    - name: luacheck run
+      run: $HOME/.luarocks/bin/luacheck ./

.luacheckrc

@@ -0,0 +1,24 @@
+unused_args = false
+allow_defined_top = true
+
+exclude_files = {".luacheckrc"}
+
+globals = {
+    "minetest", "core",
+
+    --mod provided
+}
+
+read_globals = {
+    string = {fields = {"split"}},
+    table = {fields = {"copy", "getn"}},
+
+    --luac
+    "math", "table",
+
+    -- Builtin
+    "vector", "ItemStack", "dump", "DIR_DELIM", "VoxelArea", "Settings", "PcgRandom", "VoxelManip", "PseudoRandom",
+
+    --mod produced
+    "default",
+}

depends.txt

@@ -1,2 +0,0 @@
-default
-dye

description.txt

@@ -1 +0,0 @@
-Adds faintly glowing coloured glass panes which can be used for stained glass windows or for gentle lighting. 

init.lua

@@ -1,5 +1,5 @@
 
-function register_pane(name, def)
+local function register_pane(name, def)
 	for i = 1, 15 do
 		minetest.register_alias("xpanes:" .. name .. "_" .. i, "xpanes:" .. name .. "_flat")
 	end

mod.conf

@@ -1 +1,3 @@
 name = abripanes
+depends = default, dye
+description = Adds faintly glowing coloured glass panes which can be used for stained glass windows or for gentle lighting.