dtbook/zedai/daisy3-to-epub3 scripts use temporary directories

 * all three scripts have a new `temp-dir` option
 * fixes daisy/pipeline-issues#283
 * fixes daisy/pipeline-issues#388
 * fixes daisy/pipeline-issues#389
Merge pull request #37 from daisy/epub3-contents-in-temporary-directories

dtbook/zedai/daisy3-to-epub3 scripts use temporary directories