t-maintscript-leak: Add new test case

Check for file descriptor leaks on kFreeBSD and Linux.
t-control-bogus: Add new test cases
t-triggers-depcycle: Do not break trigger cycles for direct dependencies
t-breaks-queue-dupe: Rename to t-queue-process-deconf-dupe
t-queue-process-deconf-dupe: Add file Replaces
t-deb-split: Only ignore the data file not the entire packaging
t-triggers: Take into account temporary workaround for apt

For now we need to make «dpkg --configure pkgname» process any pending
triggers, because apt is not doing it by itself. During the 1.18.x cycle
this workaround will be reverted. Make the test cope with this for now.