[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/shortcut.py

@@ -0,0 +1,69 @@
+# pylint: disable=C0112,R0903
+
+"""Shows a widget per user-defined shortcut and allows to define the behaviour
+when clicking on it.
+
+For more than one shortcut, the commands and labels are strings separated by
+a demiliter (; semicolon by default).
+
+For example in order to create two shortcuts labeled A and B with commands
+cmdA and cmdB you could do:
+
+ ./bumblebee-status -m shortcut -p shortcut.cmd='ls;ps' shortcut.label='A;B'
+
+Parameters:
+    * shortcut.cmds  : List of commands to execute
+    * shortcut.labels: List of widgets' labels (text)
+    * shortcut.delim : Commands and labels delimiter (; semicolon by default)
+
+
+contributed by `cacyss0807 <https://github.com/cacyss0807>`_ - many thanks!
+"""
+
+import logging
+
+LINK = "https://github.com/tobi-wan-kenobi/bumblebee-status/wiki"
+LABEL = "Click me"
+
+import core.module
+import core.input
+import core.decorators
+
+
+class Module(core.module.Module):
+    @core.decorators.every(minutes=60)
+    def __init__(self, config, theme):
+        super().__init__(config, theme, [])
+
+        self.__labels = self.parameter("labels", "{}".format(LABEL))
+        self.__cmds = self.parameter("cmds", "firefox {}".format(LINK))
+        self.__delim = self.parameter("delim", ";")
+
+        self.update_widgets()
+
+    def update_widgets(self):
+        """ Creates a set of widget per user define shortcut."""
+
+        cmds = self.__cmds.split(self.__delim)
+        labels = self.__labels.split(self.__delim)
+
+        # to be on the safe side create as many widgets as there are data (cmds or labels)
+        num_shortcuts = min(len(cmds), len(labels))
+
+        # report possible problem as a warning
+        if len(cmds) is not len(labels):
+            logging.warning(
+                "shortcut: the number of commands does not match "
+                "the number of provided labels."
+            )
+            logging.warning("cmds : %s, labels : %s", cmds, labels)
+
+        for idx in range(0, num_shortcuts):
+            cmd = cmds[idx]
+            label = labels[idx]
+
+            widget = self.add_widget(full_text=label)
+            core.input.register(widget, button=core.input.LEFT_MOUSE, cmd=cmd)
+
+
+# vim: tabstop=8 expandtab shiftwidth=4 softtabstop=4