Fix a typo and strip some whitespace.

pep-0302.txt

@@ -223,11 +223,11 @@ Specification part 1: The Importer Protocol
 
         loader.load_module(fullname)
 
-    This method returns the loaded module or raises and exception,
+    This method returns the loaded module or raises an exception,
     preferably ImportError if an existing exception is not being
     propagated.  If load_module() is asked to load a module that it
     cannot, ImportError is to be raised.
-    
+
     In many cases the importer and loader can be one and the same
     object: importer.find_module() would just return self.
 
@@ -384,7 +384,7 @@ Optional Extensions to the Importer Protocol
 
         d = os.path.dirname(__file__)
         data = __loader__.get_data(os.path.join(d, "logo.gif"))
-    
+
     The following set of methods may be implemented if support for (for
     example) Freeze-like tools is desirable.  It consists of three
     additional methods which, to make it easier for the caller, each of
@@ -514,7 +514,7 @@ Open Issues
     a new module implementing a subset of ihooks as a new-style
     importer, or add a hookable built-in path importer object.
 
-    There is no specific support within this PEP for "stacking" hooks. 
+    There is no specific support within this PEP for "stacking" hooks.
     For example, it is not obvious how to write a hook to load modules
     from ..tar.gz files by combining separate hooks to load modules from
     .tar and ..gz files.  However, there is no support for such stacking