Duplicate workflow / state names possible

Same with workflow names... at least a confirmation message would be helpful to avoid confusion.

Okay now, this is the last patch for today...

it's a bit bigger than the others. What I'm doing here is:

• workflow_add_form_validate()
  • CHECK FOR DUPLICATE WORKFLOW NAME
• workflow_add_form_submit()
  • set a watchdog message
  • get rid of the "theme('placeholder')" cruft (this is automatically handled by Drupal 5)
  • theme message as warning ("You should add states to your workflow")
• workflow_delete_form_submit()
  • set a watchdog message (consistently moved from workflow_deletewf())
  • get rid of the "theme('placeholder')" cruft
• theme_workflow_edit_form()
  • set a meaningful title
  • set a warning if author may not perform any transition (moved from validate: it's best to set the message then, when the user has a chance to fix the problem, and not afterwards. Also rewritten: shorter. It is always triggered, even when there is no transition at all - a warning is no error, so this doesn't hurt.)
• workflow_edit_form_validate()
  • use existing function instead of own query
  • moved warning to form
  • reworded error messages consistently
  • erroneous field now marked with red border
• workflow_edit_form_submit()
  • reworded message consistently
  • consistently use "drupal_goto"
• workflow_state_add_form()
  • use existing function instead of own query
  • get rid of the "theme('placeholder')" cruft
  • set a meaningful title
  • moved "$form['sid']" further up, so we don't need to check again
• workflow_state_add_form_validate()
  • check if 'edit' or 'create'
  • CHECK FOR DUPLICATE STATE NAME (but make sure the supposed duplicate is not the state we're editing)
  • erroneous field now marked with red border
• workflow_state_add_form_submit()
  • check if 'edit' or 'create'
  • set a watchdog message if 'create'
  • set a specific message
  • consistently use "drupal_goto"
• workflow_state_delete_form_submit()
  • set a watchdog message
• workflow_actions_remove_confirm_submit()
  • get rid of the "theme('placeholder')" cruft
  • consistently use "drupal_goto"
• workflow_deletewf()
  • consistently move watchdog message to workflow_delete_form_submit()
  • consistently use "drupal_goto"
• workflow_get_state()
  • add as a new function (sure to be needed elsewhere)
• workflow_cron()
  • get rid of the "theme('placeholder')" cruft

I tested this as much as possible and it worked out very well. Please test it yourself. I expect no new bugs, but if there is a minor one, please commit the patch anyway and tell me what to correct. Rest assured, the total count of bugs will go down with this ;-) Of the rest I'll take care, as I need this module in a perfect condition for a project...