implement wlr-gamma-control-unstable-v1

wire/zwlr_gamma_control_manager_v1.txt

@@ -0,0 +1,7 @@
+request get_gamma_control {
+    id: id(zwlr_gamma_control_v1) (new),
+    output: id(wl_output),
+}
+
+request destroy (destructor) {
+}

wire/zwlr_gamma_control_v1.txt

@@ -0,0 +1,13 @@
+event gamma_size {
+    size: u32,
+}
+
+request set_gamma {
+    fd: fd,
+}
+
+event failed {
+}
+
+request destroy (destructor) {
+}