Detect which stdiostream implementation to use

From: Lukas Nellen <lukas@nucleares.unam.mx>

The HAVE_BOOT_IOSTREAMS detection is broken, since root's config.h
gets loaded, no the one from fdeventlib.
---
 FdUtil/src/FdStdioStream.hh |    8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/FdUtil/src/FdStdioStream.hh b/FdUtil/src/FdStdioStream.hh
index 9bcdf43..decaa58 100644
--- a/FdUtil/src/FdStdioStream.hh
+++ b/FdUtil/src/FdStdioStream.hh
@@ -30,7 +30,7 @@
  #include <stdiostream.h>
 #else
  // provide a compatible solution for gcc >= 3.0
- #if (!defined DPA && defined(__GNUC__)) || (HAVE_BOOST_IOSTREAMS == 0)
+ #if (!defined DPA && defined(__GNUC__)) || (!defined(__clang__) && HAVE_BOOST_IOSTREAMS == 0)
   // use GNU extension to 'fake' stdiostream.
   #include <ostream>
   #include <ext/stdio_filebuf.h>
@@ -55,7 +55,7 @@ typedef std::ostdiostream OstdioStream;
 
 #else
 
- #if (!defined DPA && defined(__GNUC__)) || (HAVE_BOOST_IOSTREAMS == 0)
+ #if (!defined DPA && defined(__GNUC__)) || (!defined(__clang__) && HAVE_BOOST_IOSTREAMS == 0)
 
 /** This class implements a backward compatible ostdiostream.
   *
@@ -65,7 +65,7 @@ typedef std::ostdiostream OstdioStream;
   */
 class OstdioStream : public std::ostream {
 public:
-    OstdioStream(FILE* f) : 
+    OstdioStream(FILE* f) :
       std::ostream( &fFilebuf ), fFilebuf(f, ios_base::out) {}
 private:
     OstdioStream();
@@ -107,7 +107,7 @@ private:
   */
 typedef boost::iostreams::stream<CFileSink>  OstdioStream;
  #endif // (!DPA && __GNUCC__) || (HAVE_BOOST_IOSTREAMS == 0)
- 
+
 #endif // __GNUC__
 
 } // namespace FdUtil