Add missing ZeroClipbpard SWF file

Flash support for ZeroClipboard is not working in project pages since
the SWF file is missing. There was a typo in the .gitignore file that
ignored "*.sw?" files.

.gitignore

@@ -3,6 +3,6 @@
 *~
 _site
 .idea
-*.sw?
+*.sw[op]
 .project
 sample-pages