Merge pull request #82 from zwimer/prefer-standard-import

Prefer `import` to `__import__`

.gitignore

@@ -7,3 +7,4 @@ dist/
 *.so
 .noseids
 *.sublime-workspace
+*.egg-info

gitdb/__init__.py

@@ -12,15 +12,13 @@
 
 def _init_externals():
     """Initialize external projects by putting them into the path"""
-    for module in ('smmap',):
-        if 'PYOXIDIZER' not in os.environ:
-            sys.path.append(os.path.join(os.path.dirname(__file__), 'ext', module))
-
-        try:
-            __import__(module)
-        except ImportError as e:
-            raise ImportError("'%s' could not be imported, assure it is located in your PYTHONPATH" % module) from e
-        # END verify import
+    if 'PYOXIDIZER' not in os.environ:
+        where = os.path.join(os.path.dirname(__file__), 'ext', 'smmap')
+        if os.path.exists(where):
+            sys.path.append(where)
+
+    import smmap
+    del smmap
     # END handle imports
 
 #} END initialization