Simple objects to deal with stack traces.  The parent object,
Devel::StackTrace, holds a number of Devel::StackTraceFrame objects
(which have the same information as is returned from caller()).  You
can step through these frames forwards and backwards as you want or
retrieve specific frames.

BUGS

** Perl 5.6.0 and caller function

There are bugs in the caller function under Perl 5.6.0 that this
module may trigger.  One common symptom is an error message like
'Bizarre copy of HASH' or 'Bizarre copy of ARRAY'.  There is no
workaround.  5.6.1 does not have this problem.
