Show ./configure invocation in crash log.

src/rev.cpp.in

@@ -49,6 +49,12 @@ const char _openttd_revision[] = "!!VERSION!!";
  */
 const char _openttd_build_date[] = __DATE__ " " __TIME__;
 
+
+/**
+ * The configure invocation used to build OpenTTD
+ */
+const char _openttd_build_configure[] = "!!CONFIGURE_INVOCATION!!";
+
 /**
  * Let us know if current build was modified. This detection
  * works even in the case when revision string is overridden by