Package history & diff & feed to show changes to tags, extras and resources

[dread]

Currently a package's history page (/package/history/xyz) and related feed only shows changes to the core package i.e. ones which create a PackageResource?. This doesn't include changes to tags, extras and resources. These need to be added.

There is the complication that the 'diff' function doesn't currently work beyond PackageResource?. Unless this is quick and simple to fix, I suggest we let the diff remain slightly broken for now.

Rufus suggests alongside the existing methods:

pkg.all_revisions()
pkg.diff()

we have ones which also include the related objects (tags, extras, resources):

pkg.all_revisions_full()
pkg.diff_full()

You could have a function which returned these related objects. Ideas:

revobjlist = [ self, resources, extras ]
list of tuples: (revobj, changed_revobjs)
list of tuples: (revobj, {objtype: [changed_revobjs]})
tuple: (rev1, {Package: [ object_id, object_id], PackageTag: [object_id, object_id2] ...}

[johnbywater]

We could also fix up the temporal model.

[dread]

Package history page now shows revisions for tag, extra and resources. Needs tidying up and adding to REST. Done in cset:dc99df3ab4bd

[dread]

Done in cset:dc99df3ab4bd cset:beb72a0aa810 cset:96bab1eb53f5 and vdm cset:bb9f97b1c4b0