Add support for Android 2.3+

There have been plenty of ppl involved in creating this version.
I don't wanna mention names as I'm sure I'd forget someone so I
just tell where help has been done:
- The partial android versions done by various ppl
- Testing on different android devices
- reviewing code (especially the in core changes)
- testing controls
- reviewing texts

A big thank you to everyone helping this to be completed!

src/keycode.h

@@ -21,6 +21,7 @@ with this program; if not, write to the Free Software Foundation, Inc.,
 #define KEYCODE_HEADER
 
 #include "irrlichttypes.h"
+#include "Keycodes.h"
 #include <IEventReceiver.h>
 #include <string>
 
@@ -57,6 +58,7 @@ protected:
 };
 
 extern const KeyPress EscapeKey;
+extern const KeyPress CancelKey;
 extern const KeyPress NumberKey[10];
 
 // Key configuration getter
@@ -65,5 +67,7 @@ KeyPress getKeySetting(const char *settingname);
 // Clear fast lookup cache
 void clearKeyCache();
 
+irr::EKEY_CODE keyname_to_keycode(const char *name);
+
 #endif