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/mke2fs.conf b/prebuilt/mke2fs.conf
new file mode 100644
index 0000000..e231d7c
--- /dev/null
+++ b/prebuilt/mke2fs.conf
@@ -0,0 +1,17 @@
+[defaults]
+	base_features = sparse_super,filetype,resize_inode,dir_index,ext_attr
+	blocksize = 4096
+	inode_size = 256
+	inode_ratio = 16384
+
+[fs_types]
+	ext2 = {
+
+	}
+	ext3 = {
+		features = has_journal
+	}
+	ext4 = {
+		features = has_journal,extent,huge_file,flex_bg,uninit_bg,dir_nlink,extra_isize
+		inode_size = 256
+	}