[shill] Add properties to Manager, Device and subclasses. Clean up unit tests

1) Pull much of the properties stuff (the maps, Register*(), Contains()) up
   into PropertyStore, and make it a class, not an interface.
2) Add proper property stuff to Manager and Device.  Move Cellular- and Wifi-
   specific properties to Cellular, CellularService, WiFi, WiFiService as
   appropriate.
3) clean up unit tests.

BUG=chromium-os:16343
TEST=unit tests

Change-Id: Iba88f384a5fbe383608cb79fa2134d978f1b81e8
Reviewed-on: http://gerrit.chromium.org/gerrit/3136
Reviewed-by: Chris Masone <cmasone@chromium.org>
Tested-by: Chris Masone <cmasone@chromium.org>
diff --git a/mock_property_store.h b/mock_property_store.h
index 4971984..8042292 100644
--- a/mock_property_store.h
+++ b/mock_property_store.h
@@ -5,7 +5,7 @@
 #ifndef SHILL_MOCK_PROPERTY_STORE_
 #define SHILL_MOCK_PROPERTY_STORE_
 
-#include "shill/property_store_interface.h"
+#include "shill/property_store.h"
 
 #include <map>
 #include <string>
@@ -17,7 +17,7 @@
 
 class Error;
 
-class MockPropertyStore : public PropertyStoreInterface {
+class MockPropertyStore : public PropertyStore {
  public:
   MockPropertyStore() {}
   virtual ~MockPropertyStore() {}