Hooks: central vtable install with restore support

Move vtable patching into hooks.cpp: one call clones the table, validates every
slot, records the originals and installs the clone. Installs happen from the
setup, game and paint threads, so the bookkeeping is mutex-protected.

Client, CInput, IVModelRender, IStudioRender and ISurface all use it, and
hooks_restore_all() can now put every interface back (previously impossible).

1 files changed, 1 insertions, 0 deletions

diff --git a/src/hl2h.h b/src/hl2h.h
index f1a1ea0..541b31b 100644
--- a/src/hl2h.h
+++ b/src/hl2h.h
@@ -11,6 +11,7 @@
 #include <pthread.h>
 #include <unistd.h>
 
+#include "hooks.h"
 #include "overlay.h"
 
 // Shared float-precision constant. More digits than a float can hold are