Halflayout: Remember width after resize

This means you can now resize it, close everything, and it will keep the
width ratio
Add shortcut to toggle window border

Defaults to Meta+U
Minor optimizations in tilingmanager

Remove an additional layout.activate and movestep handling (only in
tilingmanager) as they do _nothing_
Release 1.1.5

Update docs

* Remember width after resize in HalfLayout

* Add a shortcut to toggle window borders
Halflayout: Don't allow moving right edge of windows at right screenedge.
HalfLayout: Fix corner cases in resizing

(Also simplify code)
Remove unused saveGeometry and restoreGeometry
Rework geometryChanged handling

This didn't actually work before, but now we can handle clients getting
borders and some other stuff better
Rework move/resize handling

This is now pseudo-animated, which is much nicer than an outline anyway
Connect the two signals that affect the tiling/floating decision anyway
Cleanup

Remove some unused or commented lines, fix a minor typo
Release 1.2

* Bugfixes (including resizing)
* "Animate" window move and resize
* Actually retile windows after they added borders etc
Only adjust geometry when it would change

This avoids an infinite loop (fortunately it'd be recursive, so the
stack would kill it)
Set tabgroups to floating

It currently doesn't appear to be possible to do otherwise, as

* tabGroupChanged is called for all clients in the tabgroup (at least
  once it's built)

* client.tabGroup is always undefined
Don't update tiles if none was moved
Release 1.2.1

* Bugfixes

* Remove tabgroup handling
Properly cut down on updates in swapTiles

The previous "fix" (8d7a5d3) broke moving majorly
Fix more halflayout resizing edgecases

Keep windows that should be at the screenedges there, while allowing
squashing windows to be moved back to reveal the squashed ones.
Put windows that reappear (e.g. unminimize) in the same tile

This appears to crash kwin quite a bit
Fix a weird crash

Somehow setting tiling_floating in addClient will crash kwin