Added glDisableVertexAttribArray and glValidateProgram

gl2.rs

@@ -342,6 +342,12 @@ pub fn enable_vertex_attrib_array(index: GLuint) {
     }
 }
 
+pub fn disable_vertex_attrib_array(index: GLuint) {
+    unsafe {
+        ll::glDisableVertexAttribArray(index);
+    }
+}
+
 pub fn finish() {
     unsafe {
         return ll::glFinish();
@@ -514,6 +520,12 @@ pub fn use_program(program: GLuint) {
     }
 }
 
+pub fn validate_program(program: GLuint) {
+    unsafe {
+        ll::glValidateProgram(program);
+    }
+}
+
 pub fn vertex_attrib_pointer_f32(index: GLuint,
                                  size: GLint,
                                  normalized: bool,