Refactor targets (ready)

- Added missing features to d3-ext.size(), height(), width()
- Removed hardcoded `target` values from components, to remove assumptions and work with other layouts better.
- Renamed `gl-framed` to `gl-main`
- Instead of putting the container name in the css class attr, moved it to `gl-container-name` attr.
- Made default stroke width 1.5, per discussion with UX.
- Added `d3.selection.prototype.selectAttr` for convenience.
- Fixed bug in `d3-ext.util.applyTarget()`
- Cleaned up some of the silly layout manager tests.