Integrate callgrind documentation into Hacking

HACKING

@@ -104,6 +104,50 @@ This file needs to be cleaned up in two ways:
 2/ There are a bunch of suppressions which need to not be suppressions, but
    instead just not be generated by valgrind.
 
+Using Callgrind with GnuCash
+----------------------------
+In order to debug with callgrind, you need to add a couple of code
+fragments around the section of code you are profiling.  This is
+easiest if you can find the function that invokes the routine(s) you
+want to profile, add the following code around the function call of
+interest.
+
+Add the following to the start of the file:
+
+#include <valgrind/callgrind.h>
+
+Add the following to the start of the calling function:
+
+static GTimeVal start, end;
+
+Add the following just before the function of interest:
+
+g_print("Start timing.\n");
+g_get_current_time(&start);
+CALLGRIND_START_INSTRUMENTATION();
+CALLGRIND_TOGGLE_COLLECT();
+
+Add the following just after the function of interest:
+
+CALLGRIND_TOGGLE_COLLECT();
+CALLGRIND_STOP_INSTRUMENTATION();
+g_get_current_time(&end);
+if (start.tv_usec > end.tv_usec) {
+  end.tv_usec += 1000000;
+  end.tv_sec  -= 1;
+}
+g_print("Callgrind enabled for %d.%6d seconds.\n",
+        (int)(end.tv_sec - start.tv_sec),
+        (int)(end.tv_usec - start.tv_usec));
+
+You will need to recompile, and then run the 'gnucash-valgrind'
+wrapper script instead of the normal 'gnucash' script.
+
+NOTE: Version 3.2 of valgrind has changed the above macros to no
+longer take an argument. In order to compile with this version of
+valgrind you will need to remove the trailing parentheses and
+semicolon.
+
 
 Look up exported and imported symbols
 -------------------------------------

libgnucash/doc/CMakeLists.txt

@@ -1,5 +1,4 @@
 set(doc_FILES
-        callgrind.txt
         constderv.html
         doxygen.cfg.in
         doxygen_main_page.c

libgnucash/doc/callgrind.txt

@@ -1,41 +0,0 @@
-In order to debug with callgrind, you need to add a couple of code
-fragments around the section of code you are profiling.  This is
-easiest if you can find the function that invokes the routine(s) you
-want to profile, add the following code around the function call of
-interest.
-
-Add the following to the start of the file:
-
-	#include <valgrind/callgrind.h>
-
-Add the following to the start of the calling function:
-
-	static GTimeVal start, end;
-
-Add the following just before the function of interest:
-
-	g_print("Start timing.\n");
-	g_get_current_time(&start);
-	CALLGRIND_START_INSTRUMENTATION();
-	CALLGRIND_TOGGLE_COLLECT();
-
-Add the following just after the function of interest:
-
-	CALLGRIND_TOGGLE_COLLECT();
-	CALLGRIND_STOP_INSTRUMENTATION();
-	g_get_current_time(&end);
-	if (start.tv_usec > end.tv_usec) {
-	  end.tv_usec += 1000000;
-	  end.tv_sec  -= 1;
-	}
-	g_print("Callgrind enabled for %d.%6d seconds.\n",
-		 (int)(end.tv_sec - start.tv_sec),
-		 (int)(end.tv_usec - start.tv_usec));
-
-You will need to recompile, and then run the 'gnucash-valgrind'
-wrapper script instead of the normal 'gnucash' script.
-
-NOTE: Version 3.2 of valgrind has changed the above macros to no
-longer take an argument. In order to compile with this version of
-valgrind you will need to remove the trailing parentheses and
-semicolon.