Add support for fallback keycodes.

This change enables the framework to synthesize key events to implement
default behavior when an application does not handle a key.
For example, this change enables numeric keypad keys to perform
their associated special function when numlock is off.

The application is informed that it is processing a fallback keypress
so it can choose to ignore it.

Added a new keycode for switching applications.

Added ALT key deadkeys.

New default key mappings:
- ESC -> BACK
- Meta+ESC -> HOME
- Alt+ESC -> MENU
- Meta+Space -> SEARCH
- Meta+Tab -> APP_SWITCH

Fixed some comments.
Fixed some tests.

Change-Id: Id7f3b6645f3a350275e624547822f72652f3defe
diff --git a/libs/ui/tests/InputPublisherAndConsumer_test.cpp b/libs/ui/tests/InputPublisherAndConsumer_test.cpp
index c6eac25..903fcaf 100644
--- a/libs/ui/tests/InputPublisherAndConsumer_test.cpp
+++ b/libs/ui/tests/InputPublisherAndConsumer_test.cpp
@@ -123,7 +123,7 @@
             << "consumer sendFinishedSignal should return OK";
 
     bool handled = false;
-    status = mPublisher->receiveFinishedSignal(handled);
+    status = mPublisher->receiveFinishedSignal(&handled);
     ASSERT_EQ(OK, status)
             << "publisher receiveFinishedSignal should return OK";
     ASSERT_TRUE(handled)
@@ -287,7 +287,7 @@
             << "consumer sendFinishedSignal should return OK";
 
     bool handled = true;
-    status = mPublisher->receiveFinishedSignal(handled);
+    status = mPublisher->receiveFinishedSignal(&handled);
     ASSERT_EQ(OK, status)
             << "publisher receiveFinishedSignal should return OK";
     ASSERT_FALSE(handled)