(svn r17416) -Codechange: move the build date/time 'determination' to rev.cpp as that's the file most likely to be regularly recompiled

src/rev.cpp.in

@@ -29,6 +29,14 @@
  */
 const char _openttd_revision[] = "!!VERSION!!";
 
+/**
+ * The text version of OpenTTD's build date.
+ * Updating the build date in this file is the safest as it generally gets
+ * updated for each revision in contrary to most other files that only see
+ * updates when they are actually changed themselves.
+ */
+const char _openttd_build_date[] = __DATE__ " " __TIME__;
+
 /**
  * Let us know if current build was modified. This detection
  * works even in the case when revision string is overriden by