Currently testers send rebuild requests by email or redmine.
Task sometimes needs rebuild, for example when a new module (like nvidia) passes to the repo (like p10) before kernel batch with the same module passes testing.

This could be implemented in many ways:

1. Request is relayed to the task creator AND additional visible task flag is updated, for example task state changes from EPERM to EPERM,REQ(REBUILD).

2. This interface could check if some subtask is actually obsoleted and needs rebuild (unmets are appeared)

2.1 and confirm rebuild request - denying rebuild request if all is ok, and require --force option if need to bypass this check;

2.2 automatically rebuilds the task.

3 Task rebuild is generally permitted for @tester ACL group.