Add a search box on problem set page. Only uses a simple algorithm, you can't use it like Google. You can search one or some of the words in the title.
NOTICE: The style of the sarch box may have some problems. when you turn the window into mobile mode, the search box will not be at the center of the page. Hope someone can make it better.
If we upload data and problem.conf online, we may cannot checkout the existing data using svn. This commit fixed it. Also changed some button's position.
If you upload the data by zip file, you can now set your own checker to problem.conf online.
NOTE: If you want to use advanced options, you'd better modify problem.conf yourself. The online problem.conf editor is only for the common situation.
Superusers now can easily add user as superuser.
BREAKING CHANGE: login into others' account is no longer supported
For safety reasons, we removed the option for superusers to login into other users' account.
If you want to recover this option, please add the code by yourself.
