Add Apache 2.4 example.
Only execute JSONcpp library check when building submit client
and throw errors when required libraries are not found.

Cherry-picked from master bf0e30de12, closes #143.
Make configuration API only available to jury and limit submissions output to valid ones.

The amount of info available through the configuration variables may not
be stellar, but it's not always published in another form, so limit access
to prevent surprises.

For submissions, it makes sense not to include invalidated submissions
by default. If someone has a usecase for getting those, we can add an extra
query parameter.
Update to reflect ICPC webservice changes
Publish standings to ICPC from jury scorecache.

You will always want to publish the final standings, never the frozen ones.
Fixes #146
Prevent mistaken standings upload while contest still running.

Fixes #146
Need to get ranks from jury point of view.

Thanks @baierjan for noticing.
Warn when judging without cgroups.

Using cgroups is highly recommended; it provides much more job control, and
in particular, Java judging without it is nowadays pretty uncomfortable.
Prepare for 4.0.4 release
Prepare for further bugfixes.
Change release date to English spelling.
Make unverified clause for submission list more precise
to filter out simulated submissions that are verified, but
do not have a judgehost.
Merge parse_scoreboard script into simulate_contest script,
add option to specify team category and update to current
database layout.

Cherry-picked from master: f7a1c0038d