Adds possible topdir to python search path

Change-Id: Ide47656071c6d17482b1e4ec0727ce316033e702
Fixes: bug #1189354

bin/heat-manage

@@ -14,6 +14,16 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
+import os
+import sys
+
+# If ../heat/__init__.py exists, add ../ to Python search path, so that
+# it will override what happens to be installed in /usr/(local/)lib/python...
+POSSIBLE_TOPDIR = os.path.normpath(os.path.join(os.path.abspath(sys.argv[0]),
+                                   os.pardir,
+                                   os.pardir))
+if os.path.exists(os.path.join(POSSIBLE_TOPDIR, 'heat', '__init__.py')):
+    sys.path.insert(0, POSSIBLE_TOPDIR)
 
 from heat.cmd import manage