[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/gpmdp.py

@@ -0,0 +1,60 @@
+# pylint: disable=C0111,R0903
+
+"""Displays information about the current song in Google Play music player.
+
+Requires the following executable:
+    * gpmdp-remote
+
+contributed by `TheEdgeOfRage <https://github.com/TheEdgeOfRage>`_ - many thanks!
+"""
+
+import core.module
+import core.widget
+import core.input
+
+import util.cli
+
+
+class Module(core.module.Module):
+    def __init__(self, config, theme):
+        widgets = [
+            core.widget.Widget(name="gpmdp.prev"),
+            core.widget.Widget(name="gpmdp.main", full_text=self.description),
+            core.widget.Widget(name="gpmdp.next"),
+        ]
+        super().__init__(config, theme, widgets)
+
+        core.input.register(
+            widgets[0], button=core.input.LEFT_MOUSE, cmd="playerctl previous"
+        )
+        core.input.register(
+            widgets[1], button=core.input.LEFT_MOUSE, cmd="playerctl play-pause"
+        )
+        core.input.register(
+            widgets[2], button=core.input.LEFT_MOUSE, cmd="playerctl next"
+        )
+
+        self.__status = None
+        self.__tags = None
+
+    def description(self, widget):
+        return self.__tags if self.__tags else "n/a"
+
+    def update(self):
+        self.__load_song()
+
+    def state(self, widget):
+        if widget.name == "gpmdp.prev":
+            return "prev"
+        if widget.name == "gpmdp.next":
+            return "next"
+        return self.__status
+
+    def __load_song(self):
+        info = util.cli.execute("gpmdp-remote current", ignore_errors=True)
+        status = util.cli.execute("gpmdp-remote status", ignore_errors=True)
+        self.__status = status.split("\n")[0].lower()
+        self.__tags = info.split("\n")[0]
+
+
+# vim: tabstop=8 expandtab shiftwidth=4 softtabstop=4