Refactor operation creation to use an operation factory registry.

Also modify GoogleKeymaster to query the operation factories to get
lists of supported modes and digests.

Change-Id: Ied30185df5dddaeaeb1106df63237757896d77db
diff --git a/rsa_operation.h b/rsa_operation.h
index 14a66c1..2c9680f 100644
--- a/rsa_operation.h
+++ b/rsa_operation.h
@@ -19,6 +19,9 @@
 
 #include <UniquePtr.h>
 
+#include <openssl/evp.h>
+#include <openssl/rsa.h>
+
 #include <keymaster/key_blob.h>
 
 #include "operation.h"