This module reports errors from the perspective of the caller of a
"clan" of modules, similar to "Carp.pm" itself. But instead of giving it
a number of levels to skip on the calling stack, you give it a pattern
to characterize the package names of the "clan" of modules which shall
never be blamed for any error. :-)
So these modules stick together like a "clan" and any error which occurs
will be blamed on the "outsider" script or modules not belonging to this
"clan".