Modify ConvConfig, Add depth dimension

proto/ModelConfig.proto

@@ -82,6 +82,12 @@ message ConvConfig {
 
   // if not set, use img_size
   optional uint32 img_size_y = 14;
+  
+  optional uint32 filter_size_z = 15 [ default = 1 ];
+  optional uint32 padding_z = 16 [ default = 1 ];
+  optional uint32 stride_z = 17 [ default = 1 ];
+  optional uint32 output_z = 18 [ default = 1 ];
+  optional uint32 img_size_z = 19 [ default = 1 ];
 }
 
 message PoolConfig {
@@ -631,4 +637,4 @@ message ModelConfig {
   // For External Machine, defining how to split a neural network
   // into multiple parts.
   optional ExternalConfig external_config = 9;
-};
+};