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/prebuilt/teamwin b/prebuilt/teamwin
new file mode 100644
index 0000000..8b13789
--- /dev/null
+++ b/prebuilt/teamwin
@@ -0,0 +1 @@
+