Some minor changes to the `patch_vary_headers` function:  * Replaced a for loop with a list comprehension.  * Used a set instead of a dict with dummy values.  * Used a bit more readable variable names.
Some minor changes to the `patch_vary_headers` function:
 * Replaced a for loop with a list comprehension.
 * Used a set instead of a dict with dummy values.
 * Used a bit more readable variable names.


git-svn-id: 554f83ef17aa7291f84efa897c1acfc5d0035373@6698 bcc190cf-cafb-0310-a4f2-bffc1f526a37

svn2github/django,svn2github/django,svn2github/django