When managing data, there will be a preview of test data or validator binary file.
But in PHP7 the prefiew of test data text file or problem.conf text file is not shown.
After my test it is caused by file_get_contents() when passing offset with -1.
It is strange that the manual on php.net in Chinese the default of $offset is -1,
but in English the default of $offset is 0. Use -1 will get nothing, 0 instead is fine.
The commit also change uojFilePreview() that can also be used as viewing binary file.
For backwards compatibility, we just set text as the default file type and no need to specify.
When printing the table of Judgement Failed items at super-manage, there is nothing shown.
It caused by using echoSubmissionsList(), arguments that 3 passed but exactly 4 expected.
So add the missing argument, and let the result hidden because we select an exact result.
Also, because of the typo of "Judgement", there will be nothing shown if
only fixed too few arguments. This commit changes it too.
When logout by clicking logout button on the top of /user/modify-profile link, you will be redirected to the login page.
But if you login immediately then you will get the login page again and loop.
It is caused by an address checking error. Now try to fix.
In order to support PHP7, change the way to operate database. PHP7
removed the mysql extension, so the old way to operate database is
not usable. This commit use a new way to operate database.
BREAKING CHANGE: the way to operate database has changed.
