Support non-hex report-filenames for reporting

[alexgit2k]

For reporting only filenames with hex-numbers are supported:

xhprof/xhprof_lib/utils/xhprof_lib.php

Lines 910 to 912 in 157fb09

	if ($k === 'run') {
	$p = implode(',', array_filter(explode(',', $p), 'ctype_xdigit'));
	}

I include the date and time in filenames to make them easier to identify, so I would like that it supports also non-hex report-filenames.