Module development and code questions

Anyone knows good automatic script/site that would take <project>.mysql and produce <project>.pgsql ?
(Of course retouches will be needed, but still)

When I'm logged on my Web site and access some node, I get 'view' and 'edit' tab options for that node's content.

Now, I would like to make a few other tab options for my nodes (say, 'move', 'history' or 'help'). I know that it can be done by adding the neccesary code directly into node.module, but that would make future upgrades very difficult (as I would need to patch core node.module after every Drupal release).

I'm using the organic groups module with a few (mainly cosmetic) modifications I've made to it, but I want to be able to let each group (whether through this module or another one) maintain nodes whereby everyone in that group can edit any node that belongs to that group, presuming the author of a node allows that. At the moment the functionality for group-based editing seems non-existent, no?

In other words, when submitting a node (perhaps only of certain node types) a user of a group can choose:
- Only I can edit this node (unix 'chmod u=w node')
- Anyone in the groups selected below can edit this node (unix 'chmod ug=w node')
- Anyone, even not in this group can edit this node (unix 'chmod a=w node')
... i.e. similar to unix's -w--w--w- permissions

Organic groups already deals with the 'r'ead permissions. You can set whether a node can be viewed by everyone, or only people in the group - that is sufficient for read.

Ideally I'm also looking for some wiki functionality here as well, whereby one can revert to a past revision of a node.

Has anyone done anything similar to this already, or can anyone point me in the right direction to achieving this? Perhaps there's a wiki module which I haven't come across yet that will sort of achieve this (they all seem to just do input filtering at the moment to format links)?

I see thiere's this node ( http://drupal.org/node/5618 ) where people have discussed something similar in the past, but it doesn't look like it came to anything.

I'm confused. Flexinode module says:

"You may define your own content types here. These will be extensions of the basic "story" node type with additional fields that you specify."

But the 'story' node type includes a body field... flexinode doesn't (just a title field by default). Sure, I can add a 'textarea' field, but this isn't ideal. In particular, when a teaser of my new node-type is shown, it has

"Body:
this is your body"

... which is ugly. I don't want the 'Body:" part.

Any ideas?

Whilst developing a module, particularly whilst I'm hacking away at the organic groups module, I need keep viewing how the site looks for various types of users, i.e. preferably by having a different browser window open for each one, e.g.: superuser; organic-group admin; regular user; user of a different organic-group; anonymous user.

When I enter a search term in "amazon item import", and hit "Search" I get a solid white blank screen. I have read all related posts on this site, but I can't seem to solve this.

My error log shows the following error:

...PHP Fatal error: Call to undefined function: domxml_open_mem() in /home/httpd/vhosts/harkeydesign.com/httpdocs/modules/amazontools/amazon.php4.inc on line 318, referer: http://harkeydesign.com/admin/amazon_import