[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/core/datetime.py

@@ -0,0 +1,45 @@
+# pylint: disable=C0111,R0903
+
+"""Displays the current date and time.
+
+Parameters:
+    * datetime.format: strftime()-compatible formatting string
+    * datetime.locale: locale to use rather than the system default
+"""
+
+from __future__ import absolute_import
+import datetime
+import locale
+
+import core.module
+import core.widget
+import core.input
+
+
+class Module(core.module.Module):
+    def __init__(self, config, theme):
+        super().__init__(config, theme, core.widget.Widget(self.full_text))
+
+        core.input.register(self, button=core.input.LEFT_MOUSE, cmd="calendar")
+        self._fmt = self.parameter("format", self.default_format())
+        l = locale.getdefaultlocale()
+        if not l or l == (None, None):
+            l = ("en_US", "UTF-8")
+        lcl = self.parameter("locale", ".".join(l))
+        try:
+            locale.setlocale(locale.LC_TIME, lcl.split("."))
+        except Exception as e:
+            locale.setlocale(locale.LC_TIME, ("en_US", "UTF-8"))
+
+    def default_format(self):
+        return "%x %X"
+
+    def full_text(self, widget):
+        enc = locale.getpreferredencoding()
+        retval = datetime.datetime.now().strftime(self._fmt)
+        if hasattr(retval, "decode"):
+            return retval.decode(enc)
+        return retval
+
+
+# vim: tabstop=8 expandtab shiftwidth=4 softtabstop=4