signage: bring in from external repo

This is b28e6f07aa48f1e2f01eb37bffa180f97a7b03bd from
https://code.hackerspace.pl/q3k/love2d-signage/. We only keep code
commited by inf and q3k, and we're both now licensing this code under
the ISC license, as per COPYING in the root of hscloud.

Change-Id: Ibeee2e6923605e4b1a17a1d295867c056863ef59
Reviewed-on: https://gerrit.hackerspace.pl/c/hscloud/+/1335
Reviewed-by: informatic <informatic@hackerspace.pl>
Reviewed-by: q3k <q3k@hackerspace.pl>
diff --git a/hswaw/signage/core/node.lua b/hswaw/signage/core/node.lua
new file mode 100644
index 0000000..42bba62
--- /dev/null
+++ b/hswaw/signage/core/node.lua
@@ -0,0 +1,16 @@
+local Node = class('Node', {})
+
+function Node:init(opts)
+    for i, n in pairs(opts) do
+        self[i] = n
+    end
+end
+
+function Node:update(dt) end
+
+function Node:beforeEnter() end
+function Node:afterEnter() end
+function Node:beforeExit() end
+function Node:afterExit() end
+
+return Node