[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/layout-xkbswitch.py

@@ -0,0 +1,42 @@
+"""Displays and changes the current keyboard layout
+
+Requires the following executable:
+    * xkb-switch
+
+contributed by `somospocos <https://github.com/somospocos>`_ - many thanks!
+"""
+
+import core.module
+import core.widget
+import core.decorators
+import core.input
+
+import util.cli
+
+
+class Module(core.module.Module):
+    @core.decorators.every(seconds=60)
+    def __init__(self, config, theme):
+        super().__init__(config, theme, core.widget.Widget(self.current_layout))
+
+        core.input.register(self, button=core.input.LEFT_MOUSE, cmd=self.__next_keymap)
+        self.__current_layout = self.__get_current_layout()
+
+    def current_layout(self, _):
+        return self.__current_layout
+
+    def __next_keymap(self, event):
+        util.cli.execute("xkb-switch -n", ignore_errors=True)
+
+    def __get_current_layout(self):
+        try:
+            res = util.cli.execute("xkb-switch")
+            return res.split("\n")[0]
+        except RuntimeError:
+            return ["n/a"]
+
+    def update(self):
+        self.__current_layout = self.__get_current_layout()
+
+
+# vim: tabstop=8 expandtab shiftwidth=4 softtabstop=4