Updated the warnings, linecache, inspect, traceback, site, and doctest modules

to work correctly with modules imported from zipfiles or via other PEP 302
__loader__ objects.  Tests and doc updates are included.

Lib/site.py

@@ -69,6 +69,8 @@ def makepath(*paths):
 def abs__file__():
     """Set all module' __file__ attribute to an absolute path"""
     for m in sys.modules.values():
+        if hasattr(m,'__loader__'):
+            continue   # don't mess with a PEP 302-supplied __file__
         try:
             m.__file__ = os.path.abspath(m.__file__)
         except AttributeError: