Implement stand-alone default DummyDb database including diagnostics

when used incorrectly

gramps/gen/dbstate.py

@@ -67,7 +67,7 @@ class DbState(Callback):
         just a place holder until a real DB is assigned.
         """
         Callback.__init__(self)
-        self.db = self.make_database("inmemorydb")
+        self.db = self.make_database("dummydb")
         self.db.load(None)
         self.db.db_is_open = False
         self.open = False
@@ -112,7 +112,7 @@ class DbState(Callback):
         """
         self.emit('no-database', ())
         self.db.close()
-        self.db = self.make_database("inmemorydb")
+        self.db = self.make_database("dummydb")
         self.db.load(None)
         self.db.db_is_open = False
         self.open = False

gramps/plugins/database/dummydb.gpr.py

@@ -0,0 +1,33 @@
+#
+# Gramps - a GTK+/GNOME based genealogy program
+#
+# Copyright (C) 2016       Tim G L Lyons
+#
+# This program is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation; either version 2 of the License, or
+# (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program; if not, write to the Free Software
+# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+#
+
+register(DATABASE,
+         id    = 'dummydb',
+         name  = _("Dummy database"),
+         name_accell  = _("Dummy Database"),
+         description =  _("Dummy Database"),
+         version = '1.0.0',
+         gramps_target_version = "5.0",
+         status = STABLE,
+         fname = 'dummydb.py',
+         databaseclass = 'DummyDb',
+         authors=['Tim Lyons'],
+         authors_email=[""],
+)