Revert "Reverted changes in Kernel/System/UnitTest.pm."

This reverts commit 193e96f16989762fec112f3550de7f6a7104694d.
Revert "Improved handling of Data::Dumper to fix problems with hash sorting on perl 5.18."

This reverts commit 68c0b1ed2de8ef9075d6f25a9bbde2f2377f4e5d.
Revert "Improved IsDeeply() by using Data::Dumper."

This reverts commit 5d106529e75e096a11c2b7c3bda86417ff9ece13.