VOL-1497 : Add more control to kv/memory access

- Added kv locking mechanism (etcd only)
- (watch) control path access whenever possible
- (watch) use a transaction for updates and merge with memory
- cleaned up vendoring
- misc changes to fix exceptions found along the way

Amendments:

- Copyright header got removed in auto-generated file
- Changed default locking to false for KV list operation
- Updated backend api to allow the passing of locking parameter

Change-Id: Ie1a55d3ca8b9d92ae71a85ce42bb22fcf1419e2c
diff --git a/vendor/golang.org/x/sys/unix/syscall_linux_riscv64.go b/vendor/golang.org/x/sys/unix/syscall_linux_riscv64.go
index 44aa122..f23ca45 100644
--- a/vendor/golang.org/x/sys/unix/syscall_linux_riscv64.go
+++ b/vendor/golang.org/x/sys/unix/syscall_linux_riscv64.go
@@ -207,3 +207,7 @@
 	}
 	return ppoll(&fds[0], len(fds), ts, nil)
 }
+
+func Renameat(olddirfd int, oldpath string, newdirfd int, newpath string) (err error) {
+	return Renameat2(olddirfd, oldpath, newdirfd, newpath, 0)
+}