[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/libvirtvms.py

@@ -0,0 +1,32 @@
+"""Displays count of running libvirt VMs.
+
+Required the following python packages:
+        * libvirt
+
+contributed by `maxpivo <https://github.com/maxpivo>`_ - many thanks!
+"""
+
+import sys
+import libvirt
+
+import core.module
+import core.widget
+import core.input
+import core.decorators
+
+
+class Module(core.module.Module):
+    @core.decorators.every(seconds=10)
+    def __init__(self, config, theme):
+        super().__init__(config, theme, core.widget.Widget(self.status))
+
+        core.input.register(self, button=core.input.LEFT_MOUSE, cmd="virt-manager")
+
+    def status(self, _):
+        conn = libvirt.openReadOnly(None)
+        if conn == None:
+            return "Failed to open connection to the hypervisor"
+        return "VMs %s" % (conn.numOfDomains())
+
+
+# vim: tabstop=8 expandtab shiftwidth=4 softtabstop=4