make importing of drawing and geo subpackages optional

diff -Naur networkx-1.9.orig/networkx/__init__.py networkx-1.9/networkx/__init__.py
--- networkx-1.9.orig/networkx/__init__.py	2014-06-25 12:02:09.000000000 -0600
+++ networkx-1.9/networkx/__init__.py	2014-06-30 12:00:00.000000000 -0600
@@ -84,6 +84,8 @@
 from networkx.linalg import *
 from networkx.tests.test import run as test
 
-import networkx.drawing
-from networkx.drawing import *
-
+try:
+    import networkx.drawing
+    from networkx.drawing import *
+except ImportError:
+    pass
diff -Naur networkx-1.9.orig/networkx/readwrite/__init__.py networkx-1.9/networkx/readwrite/__init__.py
--- networkx-1.9.orig/networkx/readwrite/__init__.py	2014-06-25 11:50:58.000000000 -0600
+++ networkx-1.9/networkx/readwrite/__init__.py	2014-06-30 12:00:00.000000000 -0600
@@ -14,4 +14,8 @@
 from networkx.readwrite.gml import *
 from networkx.readwrite.graphml import *
 from networkx.readwrite.gexf import *
-from networkx.readwrite.nx_shp import *
+
+try:
+    from networkx.readwrite.nx_shp import *
+except ImportError:
+    pass