Fix (unintentional) linkage of HAVE_BUTTON_DATA with HAVE_TOUCHSCREEN

Defining HAVE_BUTTON_DATA without simultaneously defining HAVE_TOUCHSCREEN
caused compile errors. (I need them separated for a scrollstrip driver.)

Change-Id: I945d3437d840035ccc0c147f8155029b403c6ec2
Reviewed-on: http://gerrit.rockbox.org/771
Reviewed-by: Amaury Pouly <amaury.pouly@gmail.com>
Reviewed-by: Thomas Martitz <kugel@rockbox.org>
fix quick screen write to config

Change-Id: Id55f81011a9ce47589d879203ca4f8fd4c54f593
Reviewed-on: http://gerrit.rockbox.org/757
Reviewed-by: Thomas Martitz <kugel@rockbox.org>
Add Dmitry Gamza and Sebastian Leonhardt to CREDITS.

Change-Id: I10c3c8963277905f3c74247fc16acc247323e30f
quickscreen: return true on USB connection.

This is consistent with other screens (pitch, id3) on the WPS and in other
places.

Change-Id: Iafae52507867ff9815a60cf44faaf09a29c55091
usb screen: Stop scrolling the entire display.

It's not easy for the originating screen to perform cleanup in case of USB
because the usb screen is invoked indirectly via default_event_handler(). To
avoid stale scrolling lines perform the cleanup in the usb screen itself.

Side effect should be no worse than scrolling lines to restart in SBSes that
show during USB.

Change-Id: I9aa491b3d4b649c0b3be70048ebcb9d817c0356c
Fix build reds caused by typos.

Change-Id: I71cdca3b6e73e29d487e0c6d02a69a31dcf3e6bf