[macros] Add escapechar setting for "outputblock" environment.

Author: tkoeppe

source/macros.tex

@@ -611,7 +611,7 @@
 #1:}}\CodeBlockSetup}{}
 
 % An environment for command / program output that is not C++ code.
-\lstnewenvironment{outputblock}{\lstset{language=}}{}
+\lstnewenvironment{outputblock}{\lstset{escapechar=@, language=}}{}
 
 % A code block in which single-quotes are digit separators
 % rather than character literals.