[modules/date] Combine to datetime module with date and time aliases

Move module "date" to "datetime" (display both date and time), and
create new aliases "time" and "date" (which only show date and time,
respectively).

bumblebee/modules/date.py

@@ -1 +1 @@
-time.py
+datetime.py

bumblebee/modules/datetime.py

@@ -0,0 +1 @@
+time.py

bumblebee/modules/time.py

@@ -1,3 +1,5 @@
+from __future__ import absolute_import
+
 import datetime
 import bumblebee.module
 
@@ -6,8 +8,12 @@ class Module(bumblebee.module.Module):
         super(Module, self).__init__(args)
 
         module = self.__module__.split(".")[-1]
+        default = "%x %X"
+        if module == "date":
+            default = "%x"
+        if module == "time":
+            default = "%X"
 
-        default = "%x" if module == "date" else "%X"
         self._fmt = args[0] if args else default