doc: Sync classref with current source

doc/classes/Camera.xml

@@ -35,6 +35,12 @@
 			<description>
 			</description>
 		</method>
+		<method name="get_frustum" qualifiers="const">
+			<return type="Array">
+			</return>
+			<description>
+			</description>
+		</method>
 		<method name="is_position_behind" qualifiers="const">
 			<return type="bool">
 			</return>

doc/classes/Node.xml

@@ -269,6 +269,15 @@
 			<description>
 			</description>
 		</method>
+		<method name="get_node_or_null" qualifiers="const">
+			<return type="Node">
+			</return>
+			<argument index="0" name="path" type="NodePath">
+			</argument>
+			<description>
+				Similar to [method get_node], but does not raise an error when [code]path[/code] does not point to a valid [code]Node[/code].
+			</description>
+		</method>
 		<method name="get_parent" qualifiers="const">
 			<return type="Node">
 			</return>

modules/csg/doc_classes/CSGShape.xml

@@ -29,6 +29,12 @@
 				Returns an individual bit on the collision mask.
 			</description>
 		</method>
+		<method name="get_meshes" qualifiers="const">
+			<return type="Array">
+			</return>
+			<description>
+			</description>
+		</method>
 		<method name="is_root_shape" qualifiers="const">
 			<return type="bool">
 			</return>