Improved font scalability for Base style

This should make it useable on hight dpi
tablets and desktops where font sizes are
larger.

Change-Id: I8c8e7688927a0b54e3f95c276c743aaa31e8a4d9
Reviewed-by: J-P Nurmi <jpnurmi@digia.com>
Reviewed-by: Gabriel de Dietrich <gabriel.dedietrich@digia.com>