TWRP-ify AOSP code

Pull in most TWRP sources
Stub out partition management code
Make it compile -- probably will not boot
Kind of a mess but have to start somewhere
diff --git a/common.h b/common.h
index a1168cd..4122e40 100644
--- a/common.h
+++ b/common.h
@@ -23,6 +23,9 @@
 extern "C" {
 #endif
 
+#define ui_print(...) fprintf(stdout, __VA_ARGS__)
+#define ui_print_overwrite(...) fprintf(stdout, __VA_ARGS__)
+
 // TODO: restore ui_print for LOGE
 #define LOGE(...) fprintf(stdout, "E:" __VA_ARGS__)
 #define LOGW(...) fprintf(stdout, "W:" __VA_ARGS__)