starting to abstract the vertext buffers

src/core/include/pw/core/matrix.hpp

@@ -57,7 +57,7 @@ struct matrix_ : matrixbase_<T, matrix_<R, C, T>>
         return *this;
     }
 
-    explicit matrix_(std::initializer_list<T> args)
+    matrix_(std::initializer_list<T> args)
 	{
 		typename std::initializer_list<T>::iterator it = args.begin();
 		for (;it != args.end();it++) data[it-args.begin()] = *it;