Added the option to parameterize www-delete and www-toggle-publish-status with return_url
In cases, these www* methods are called programmatically, these can be
now parameterized with an "-return_url" parameter to achieve
e.g. workflow-specific behavior.
Many thanks to Thomas Renner for the analysis on
www-toggle-publish-status.
Version number bumped to 5.10.1d18