Make PSE submissions their own CT rather than using Projects

[jim]

It turns out the approach I went for originally to save a little work cost us more in the long run, so we need a part of the PSE rebuilt...

• Ideally we'd get the PSE to submit a new content type and map the submission back to a 'proper' project when the moderator accepts.
• Since I've already written the code to take another form and convert to a Project, I might as well make the new CT plug into the existing stuff.
• All the work I've done so far is modular, and able to be tweaked and reused...
• As is the code that 'accepts' a project during moderation.

So the changes to fix the issues in several other tickets are:

1. Add a new CT called 'PSE submission', set up permissions accordingly.
2. Change existing moderations views to use the new CT.
3. Move the 'Needs Moderation' field from Projects to PSE submission CT
4. Various small code fixes.
5. Testing.

This makes the following tickets become obsolete/duplicates of this: #428, #430, #444, #439 -- will update them accordingly.

I'll make a start now, finish up tomorrow.

[jim]

OK all the points above are now done locally, except 3) which was unneeded. That 'Needs Moderation' field should be deleted next time I bring through the Project changes -- I've added to #384.

Am now updating the Features and moving though Git... Should be ready for release in an hour or so...

[jim]

This one's now fixed...