More ways to judge

[BillYang2016]

This issue is opened long time ago,but hasn't been regarded.
Not only special judge required,but also submit answer & interactive problems are important.
Though Traditional problems are important,we can frequently see new submit answer & interactive problems on many contests,they are more welcomed.
However,I don't have the ability to submit a PR too,sorry for that.
#387

[ksyx]

#397

[q234rty]

For sumbit answer problems:vijos/jd4#42

[BillYang2016]

so special judge & interactive problems should be regarded seriously?

[breezewish]

Just a note: SPJ is supported now.

[twd2]

secret

[zzhou612]

So how can I add a special judge problem? Is the "special judge" feature available in the master branch?