adding "make valgrind" running the full regression tests (except python

* Makefile.am: adding "make valgrind" running the full regression
  tests (except python ones) under Valgrind (using valgrind -q
  which was kindly added by the author).
* valid.c: stupid bug pinpointed by Valgrind, the regression tests
  passes cleanly now except an obcure floating point initialization
  raised in log10() in one XPath regression test ???
* tree.c: edited some comments to close #75244
Daniel
diff --git a/tree.c b/tree.c
index 84620c7..0d36ca9 100644
--- a/tree.c
+++ b/tree.c
@@ -5888,6 +5888,8 @@
  * @format: is formatting allowed
  *
  * Dump an XML node list, recursive behaviour,children are printed too.
+ * Note that format = 1 provide node indenting only if xmlIndentTreeOutput = 1
+ * or xmlKeepBlanksDefault(0) was called
  */
 static void
 xmlNodeListDump(xmlBufferPtr buf, xmlDocPtr doc, xmlNodePtr cur, int level,
@@ -5923,6 +5925,8 @@
  * @format: is formatting allowed
  *
  * Dump an XML node, recursive behaviour,children are printed too.
+ * Note that format = 1 provide node indenting only if xmlIndentTreeOutput = 1
+ * or xmlKeepBlanksDefault(0) was called
  */
 void
 xmlNodeDump(xmlBufferPtr buf, xmlDocPtr doc, xmlNodePtr cur, int level,
@@ -6271,6 +6275,8 @@
  * @encoding:  an optional encoding string
  *
  * Dump an XML node list, recursive behaviour, children are printed too.
+ * Note that format = 1 provide node indenting only if xmlIndentTreeOutput = 1
+ * or xmlKeepBlanksDefault(0) was called
  */
 static void
 xmlNodeListDumpOutput(xmlOutputBufferPtr buf, xmlDocPtr doc,
@@ -6307,6 +6313,8 @@
  * @encoding:  an optional encoding string
  *
  * Dump an XML node, recursive behaviour, children are printed too.
+ * Note that format = 1 provide node indenting only if xmlIndentTreeOutput = 1
+ * or xmlKeepBlanksDefault(0) was called
  */
 void
 xmlNodeDumpOutput(xmlOutputBufferPtr buf, xmlDocPtr doc, xmlNodePtr cur,
@@ -6470,6 +6478,8 @@
  * @format:  should formatting spaces been added
  *
  * Dump an XML document.
+ * Note that format = 1 provide node indenting only if xmlIndentTreeOutput = 1
+ * or xmlKeepBlanksDefault(0) was called
  */
 static void
 xmlDocContentDumpOutput(xmlOutputBufferPtr buf, xmlDocPtr cur,
@@ -6526,6 +6536,8 @@
  * Dump the current DOM tree into memory using the character encoding specified
  * by the caller.  Note it is up to the caller of this function to free the
  * allocated memory.
+ * Note that format = 1 provide node indenting only if xmlIndentTreeOutput = 1
+ * or xmlKeepBlanksDefault(0) was called
  */
 
 void
@@ -6639,6 +6651,8 @@
  *
  * Dump an XML document in memory and return the #xmlChar * and it's size.
  * It's up to the caller to free the memory.
+ * Note that format = 1 provide node indenting only if xmlIndentTreeOutput = 1
+ * or xmlKeepBlanksDefault(0) was called
  */
 void
 xmlDocDumpFormatMemory(xmlDocPtr cur, xmlChar**mem, int *size, int format) {