Fix porting bug to make Comparator actually compare correctly.

Fix porting bug to make Comparator actually compare correctly.

This was crashing std::sort which apparenty for optimization reasons
requires a < b to imply !(b < a). qSort, on the other hand, avoids the
problem. The crash only showed up with sufficiently large keyrings, as
apparently std::sort, likely again for optimization reasons, uses a
simpler sort for shorter containers, which doesn't run into this issue.
Fun bug, took Volker and me most of the train ride from Osnabrueck to
Berlin to figure out why and how this happens, boring our travel
companion to tears in the process. Geek out!

BUG: 238708

svn path=/trunk/KDE/kdepim/libkpgp/; revision=1131243