Add workflow_access module (here's the code to commit)

After a short email conversation with Mark Fredrickson about workflow based node permissions, it seemed to be feasible to grab the workflow_access code from na_arbitrator (which was discontinued after Drupal 5.0 got most of it's functionality included). Now because I needed a workflow and role based access scheme for my thesis project anyway, I grabbed the code and updated it for Drupal 5.0. What's new:

- added an .info file
- added postgresql compatibility (but not tested it)
- removed the "hunmonk dependency hacks", which are not required now dependecies being part of Drupal core
- applied the new node access API based on the fantastic node_access_example module
- done a general clean up, less magic for form altering and so on... documented special stuff like the -1 rid used, removed many temp variables and so on
- used Drupal constants where available, done away with magic role ID numbers
- added phpdoc comments where possible

Tested the module on PHP 5.1 with MySQL 5.0 and workflow module latest DRUPAL-5 branch version (1.54.2.6). The access editing seems to work nicely, data is stored, permissions are only granted when I rule them.

I would welcome the inclusion of this module as part of the workflow module suite.