adding the pattern node selection code. Inheried in part from libxslt but

* pattern.c include/libxml/pattern.h: adding the pattern node
  selection code. Inheried in part from libxslt but smaller.
* Makefile.am configure.in include/libxml/xmlversion.h.in:
  integrated the pattern module, made it a configure time option
* xmllint.c: added --pattern to test when doing --stream
Daniel
diff --git a/Makefile.am b/Makefile.am
index 11745e5..f10ed55 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -27,7 +27,7 @@
 		catalog.c globals.c threads.c c14n.c \
 		xmlregexp.c xmlschemas.c xmlschemastypes.c xmlunicode.c \
 		triostr.c trio.c xmlreader.c relaxng.c dict.c SAX2.c \
-		xmlwriter.c legacy.c chvalid.c
+		xmlwriter.c legacy.c chvalid.c pattern.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  \
@@ -36,7 +36,7 @@
 		catalog.c globals.c threads.c c14n.c \
 		xmlregexp.c xmlschemas.c xmlschemastypes.c xmlunicode.c \
 		xmlreader.c relaxng.c dict.c SAX2.c \
-		xmlwriter.c legacy.c chvalid.c
+		xmlwriter.c legacy.c chvalid.c pattern.c
 endif
 
 DEPS = $(top_builddir)/libxml2.la