make importing of drawing and geo subpackages optional

diff -Naur networkx-networkx-1.10.orig/networkx/__init__.py networkx-networkx-1.10/networkx/__init__.py
--- networkx-networkx-1.10.orig/networkx/__init__.py	2015-10-30 15:41:35.000000000 -0600
+++ networkx-networkx-1.10/networkx/__init__.py	2015-11-24 09:34:20.741823392 -0700
@@ -95,5 +95,8 @@
 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-networkx-1.10.orig/networkx/readwrite/__init__.py networkx-networkx-1.10/networkx/readwrite/__init__.py
--- networkx-networkx-1.10.orig/networkx/readwrite/__init__.py	2015-10-30 15:41:35.000000000 -0600
+++ networkx-networkx-1.10/networkx/readwrite/__init__.py	2015-11-24 09:34:46.539738141 -0700
@@ -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