Make page tree display in table layout?

[cogat]

Having the page tree in a draggable JS tree causes the following problems:

• accidental dragging (which doesn't work out of the box, and bypasses the publishing framework causing instant changes to URLs)
• inability to select page items for Admin Actions.
• inability to sort by columns or filter
• confusing/broken display when the window is narrow or has many columns
• right-click is disabled

The only things the JS transformation accomplishes (that we use) are:

• Indents indicating tree shape
• folding parents and children

I propose we render the page list as a normal table, with indented titles, and classes on each line that indicates all parents of that line. No drag/drop. Toggling a parent toggles the visibility of lines with that parent.

[cogat]

The commit above ditches the JS injection of a nested list, which replaced the table in the changelist. Instead, we're now grafting tree indentation and disclosure controls into the table. Drag/drop has gone, but it wasn't working or much use to us anyway. There are still up/down arrows for incremental reordering.

We can now search all pages, not just the top level.

[cogat]

TODO:

• store disclosure state in cookies
• more granular toggle state (store 'collapsed-by' data on the row), so if you collapse a child, it stays collapsed if you collapse and expand its parent.