latexmk better cleanup

.latexmkrc

-$pdf_mode = 1;  # use pdflatex
-$bibtex_use = 2;  # use bibtex
+# use pdflatex
+$pdf_mode = 1;
+
+# use bibtex
+$bibtex_use = 2;
+$clean_ext .= " run.xml";
+
+# use and auxilary folder for temp files
 $aux_dir = './.aux/';
 
 # put the ./src subfolder on searchpath