[Suggestion] Allow users to modify splash.

[beatstar]

Users with Level 5 permissions cannot currently modify the splash page

for the /v/GAs. Currently only the webmaster or users with FTP access can modify this page. Given the page is a high traffic one, but infrequently updated, users with Level 5 permissions or those with a special permission assigned (e.g: splash_edit) should be able to update the image for each year.