preparing release of 2.6.18 updated docs and rebuilt reactivated gcc

* NEWS configure.in testapi.c doc/*: preparing release of 2.6.18
  updated docs and rebuilt
* libxml.spec.in: reactivated gcc profiling for gcc >= 4.0.0
Daniel
diff --git a/libxml.spec.in b/libxml.spec.in
index b4f3761..481f88e 100644
--- a/libxml.spec.in
+++ b/libxml.spec.in
@@ -65,7 +65,7 @@
 # initial test spec. This really doesn't work okay for most tests done.
 #
 GCC_VERSION=`gcc --version | grep "^gcc" | awk '{ print $3 }' | sed 's+\([0-9]\)\.\([0-9]\)\..*+\1\2+'`
-if [ $GCC_VERSION -eq 34 ]
+if [ $GCC_VERSION -ge 34 ]
 then
     PROF_GEN='-fprofile-generate'
     PROF_USE='-fprofile-use'