All its members are comparable themselves, so this can be defaulted.
Making it comparable will allow us, among other things, to check if a
list of symbols (i.e., the result of calling the symbolicate functions)
is equal or not to another, which in turn will allow us to avoid
refreshing the SystemMonitor's Stack tab when successive symbolicated
stacks are the same.
This small patch allows SystemMonitor's Stack tab to show the name of
the ELF object to which the displayed address refers to. This gives a
bit more of contextual information to the viewer.
A better to show this is probably a table, but I'm not that familiar yet
with the GUI framework in general, so I'm keeping things simple.
This removes all the hard-coded kernel base addresses from userspace
tools.
One downside for this is that e.g. Profiler no longer uses a different
color for kernel symbols when run as a non-root user.
