Log new defined variables for section

[cadorn]

The trace function is a handy tool, however, it gives quite a bit of
information. It would be nice to have a simpler start/end variable
trace that logs each variable one at a time

For example:

$start = array_keys(get_defined_vars());
$end = array_keys(get_defined_vars());
$log_variables = array_diff($start, $end)
foreach($log_variables as $log_variable)
    $console->log($log_variable);

This needs work, I understand. But the point is instead of adding
10-20 separate log statements in a section of code, you could just
have one start/end. This is different from trace(); because in many
PHP frameworks that globally load numerous functions, the trace output
can become muddy when quickly looking for a certain variable value.

Reported: http://groups.google.com/group/firephp-dev/browse_thread/thread/df5f91ac8afd113c