fixing #61290 "namespace nodes have no parent" long standing divergence

* xpath.c: fixing #61290 "namespace nodes have no parent"
  long standing divergence from the XPath REC. NodeSets
  simply hold a copy of namespace nodes and those node ->next
  points to the parent (which may not be the node carrying the
  definition).
* include/libxml/xpath.h: flagged but didn't added a possible
  speedup
* DOCBparser.c HTMLparser.c: removed some warnings from push
  parser due to new state being added.
* tree.c: new fix from Boris Erdmann
* configure.in c14n.c include/libxml/c14n.h testC14N.c: added
  the XML Canonalization support from Aleksey Sanin
Daniel
diff --git a/Makefile.am b/Makefile.am
index b16d758..7047c0a 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -5,7 +5,8 @@
 
 INCLUDES = -I@srcdir@/include -I$(top_builddir)/include @THREAD_CFLAGS@ @Z_CFLAGS@ 
 
-noinst_PROGRAMS=testSAX testHTML testXPath testURI testDocbook testThreads
+noinst_PROGRAMS=testSAX testHTML testXPath testURI testDocbook testThreads \
+                testC14N
 
 bin_PROGRAMS = xmllint xmlcatalog
 
@@ -21,14 +22,14 @@
 		parser.c tree.c hash.c list.c xmlIO.c xmlmemory.c uri.c  \
 		valid.c xlink.c HTMLparser.c HTMLtree.c debugXML.c xpath.c  \
 		xpointer.c xinclude.c nanohttp.c nanoftp.c DOCBparser.c \
-		catalog.c globals.c threads.c triostr.c trio.c
+		catalog.c globals.c threads.c c14n.c triostr.c trio.c
 
 else
 libxml2_la_SOURCES = SAX.c entities.c encoding.c error.c parserInternals.c  \
 		parser.c tree.c hash.c list.c xmlIO.c xmlmemory.c uri.c  \
 		valid.c xlink.c HTMLparser.c HTMLtree.c debugXML.c xpath.c  \
 		xpointer.c xinclude.c nanohttp.c nanoftp.c DOCBparser.c \
-		catalog.c globals.c threads.c
+		catalog.c globals.c threads.c c14n.c
 
 endif
 
@@ -70,6 +71,11 @@
 testXPath_DEPENDENCIES = $(DEPS)
 testXPath_LDADD= $(LDADDS)
 
+testC14N_SOURCES=testC14N.c
+testC14N_LDFLAGS = 
+testC14N_DEPENDENCIES = $(DEPS)
+testC14N_LDADD= $(LDADDS)
+
 testThreads_SOURCES=testThreads.c
 testThreads_LDFLAGS = 
 testThreads_DEPENDENCIES = $(DEPS)