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/zsyscall_darwin_amd64.s b/vendor/golang.org/x/sys/unix/zsyscall_darwin_amd64.s
index da9b900..1a39151 100644
--- a/vendor/golang.org/x/sys/unix/zsyscall_darwin_amd64.s
+++ b/vendor/golang.org/x/sys/unix/zsyscall_darwin_amd64.s
@@ -108,6 +108,8 @@
 	JMP	libc_chown(SB)
 TEXT ·libc_chroot_trampoline(SB),NOSPLIT,$0-0
 	JMP	libc_chroot(SB)
+TEXT ·libc_clock_gettime_trampoline(SB),NOSPLIT,$0-0
+	JMP	libc_clock_gettime(SB)
 TEXT ·libc_close_trampoline(SB),NOSPLIT,$0-0
 	JMP	libc_close(SB)
 TEXT ·libc_dup_trampoline(SB),NOSPLIT,$0-0