Converting $dst_dir to absolute path before chdir

- Before chdir to $src_dir, $dst_dir should be converted to the
absolute path.
- If $dst_dir leaves as its default “.”, all converted files will be
written in the current dir. “./pages” is set to the default.
Minor fix

$dst_dir default changed to “./pages” from “./page”.
Merge pull request #2 from je1sgh/master

Converting $dst_dir to absolute path before chdir