Add colored rectangles around active client

This doesn't currently work yet, maybe because of a KWin bug
Always use "new" with Qt.rect
Fix adding windows when compositing is disabled
Always use "var i" in for-loops
Add manual tiling mode
Hack around endless loops

This isn't perfect, but should hold up until the underlying issue is fixed
Stop updating early when tiling object isn't useractive
Add semicolons after function declaration

Don't rely on javascripts fancy insertion.
Unify manual tiling and tiling disabling

Manual tiling is effectively just enabling and disabling the layout.

This means that it's now also easy to tile once in an inactive layout,
not just when globally disabled.
Implement full, layout-agnostic, proper resizing.

Removed more than 100 lines of code.
Move getTilingArea to util

This may be needed elsewhere
Cleanup doResize a bit

The typical: no var in a for-loop, missing comments
Remove HACK in Tiling.resizeTile

This broke min/max handling with the new resizing code
Keep client's width/height when min/max is violated

This is because min/max is sometimes not a valid size (because it
includes the border)
Only keep client's _height_ when too small

This is the only case that doesn't work
Turn off electricBorderMaximize while resizing a client

This prevents accidental maximization
Define master in spirallayout
Add rectToString function

Useful for debugging
Use geometryShapeChanged

geometryChanged fires more often
Only use maxSize if it's greater than 0