Support non-orientation aware keyboards and other devices.

Fixed a bug with dpad keys on external keyboards being rotated
according to the display orientation by adding a new input device
configuration property called "keyboard.orientationAware".

Added a mechanism for overriding the key layout and key character
map in the input device configuration file using the new
"keyboard.layout" and "keyboard.characterMap" properties.

Also added "trackball.orientationAware", "touch.orientationAware" and
"touch.deviceType" configuration properties.

Rewrote the configuration property reading code in native code
so that it can be used by EventHub and other components.

Added basic support for installable idc, kl, and kcm files
in /data/system/devices.  However, there is no provision for
copying files there yet.

Disabled long-press character pickers on full keyboards so that
key repeating works as expected.

Change-Id: I1bd9f0c3d344421db444e7d271eb09bc8bab4791