Input: Add Euro and Dollar key codes

Most newer Acer laptops (from 2005 onwards) now ship with an extra Dollar
and Euro key either side of the 'Up' arrow. These cannot be mapped in the
traditional way, since they are not combination keys.

Signed-off-by: Carlos Corbacho <cathectic@gmail.com>
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>