Add tabular history view

[Cobra]

Sometimes it's very useful to get a quick overview of the history without having to compare two revisions. Up to now it's necessary to call ​http://osm.mapki.com/history/, but this could be done in the history viewer as well.

The current "diff table" view and the tabular view could be displayed in separate tabs (maybe add a configuration option to set one view as default or remember the selected view).

The table itself should resemble the web version with a version/changeset part (Version, user, CT, changeset, date), a tag part with all tags ever added and a object specific part (nodes: lat, lon; ways: nodes; relations: members and their roles).

Nice-to-have:

• don't scroll the version/changeset part and the first column with the descriptions to have this information always visible.
• some sort of visualization of changed order of nodes in ways or relation members.

[Cobra]

I've looked into the existing history browser code, but couldn't find a quick way to properly isolate the current view so the new one could be added without breaking anything. I'd like to try implementing this new view, but I need some help with at least this problem.