Add note that maintainer-* make targets replace normal ones.
Put maintainer documentation in more natural order.
Move "declare(ticks = 1)" code to common initsignals() function.
Add configure_input auto-generate string.
Fix indexing over teams and improve layout of array() call.
Fix SQL event insert query and refer to correct alternate
location in case of verification not required.
Rename FIXED_TEAM to FIXED_USER in domserver config.
Partial update to new JSON API specification.
Added support for public sample testcases.

Contestants can view testcases marked as sample as well as their
program output on these cases.

WARNING: this can and will leak information about the problem like
timelimit and more.

Cherry-picked from: 177a655d
Add option to enable teams to see sample testcase run output.
Also clean up rankcache_* tables when refreshing cache.
Update comments for support of HTTP methods, simplify code
and break up some long lines. No functional change.
Remove essentially duplicate argument 'callback' in
RestAPI.provideFunction().
Fix HTML validation issue.
Include 'sample' in SQL query and put it into a function for reuse.
Suppress notice of undefined index.