Among others:
- Use `apply` instead of `commit` when saving shared preferences.
- Avoid inlined Api
- Remove unused resources

The conversion into px was done twice, leading to wrong values.

A large margin in portrait mode is desirable but generally not in
landscape mode.

A separate option is needed, the +25dp offset wasn't enough.

Dimens weren't refreshed when the orientation changed. Dimens are not
the right solution anyway, use scaling factors instead.

Space between the keys and margin on the left and right edges of the
screen.

Instead of a fixed size that don't work at all for bigger screens.

Other tweaks:
- Use the value-land dimens to vary 'extra_horizontal_margin'
- Move label size to Config, because it can change at runtime (rotation)
- Slightly decrease the size of "long" symbols

Use xmllint.
Re-indent Java files using spaces.