Add Shockwave Flash.

(backport candidate?)
diff --git a/Lib/mimetypes.py b/Lib/mimetypes.py
index ddd1fa4..a909366 100644
--- a/Lib/mimetypes.py
+++ b/Lib/mimetypes.py
@@ -430,6 +430,7 @@
     '.src'    : 'application/x-wais-source',
     '.sv4cpio': 'application/x-sv4cpio',
     '.sv4crc' : 'application/x-sv4crc',
+    '.swf'    : 'application/x-shockwave-flash',
     '.t'      : 'application/x-troff',
     '.tar'    : 'application/x-tar',
     '.tcl'    : 'application/x-tcl',