[core] restructure to allow PIP packaging

OK - so I have to admit I *hate* the fact that PIP seems to require a
subdirectory named like the library.

But since the PIP package is something really nifty to have (thanks to
@tony again!!!), I updated the codebase to hopefully conform with what
PIP expects. Testruns so far look promising...

bumblebee_status/modules/contrib/brightness.py

@@ -0,0 +1,70 @@
+# pylint: disable=C0111,R0903
+
+"""Displays the brightness of a display
+
+Parameters:
+    * brightness.step: The amount of increase/decrease on scroll in % (defaults to 2)
+
+contributed by `TheEdgeOfRage <https://github.com/TheEdgeOfRage>`_ - many thanks!
+"""
+
+import glob
+import shutil
+
+import core.module
+import core.widget
+import core.input
+import core.decorators
+
+import util.cli
+
+
+class Module(core.module.Module):
+    @core.decorators.every(seconds=30)
+    def __init__(self, config, theme):
+        super().__init__(config, theme, core.widget.Widget(self.brightness))
+
+        self.__brightness = "n/a"
+        self.__readcmd = None
+        step = self.parameter("step", 2)
+
+        if shutil.which("light"):
+            self.__readcmd = self.__light
+            self.register_cmd("light -A {}%".format(step), "light -U {}%".format(step))
+        elif shutil.which("brightnessctl"):
+            self.__readcmd = self.__brightnessctl
+            self.register_cmd(
+                "brightnessctl s {}%+".format(step), "brightnessctl s {}%-".format(step)
+            )
+        else:
+            self.__readcmd = self.__xbacklight
+            self.register_cmd(
+                "xbacklight +{}%".format(step), "xbacklight -{}%".format(step)
+            )
+
+    def register_cmd(self, up_cmd, down_cmd):
+        core.input.register(self, button=core.input.WHEEL_UP, cmd=up_cmd)
+        core.input.register(self, button=core.input.WHEEL_DOWN, cmd=down_cmd)
+
+    def brightness(self, widget):
+        return self.__brightness
+
+    def __light(self):
+        return util.cli.execute("light").strip()
+
+    def __brightnessctl(self):
+        m = util.cli.execute("brightnessctl m").strip()
+        g = util.cli.execute("brightnessctl g").strip()
+        return float(g) / float(m) * 100.0
+
+    def __xbacklight(self):
+        return util.cli.execute("xbacklight -get").strip()
+
+    def update(self):
+        try:
+            self.__brightness = "{:3.0f}%".format(float(self.__readcmd()))
+        except:
+            self.__brightness = "n/a"
+
+
+# vim: tabstop=8 expandtab shiftwidth=4 softtabstop=4