Update Makefile.include

Proposed changing c++0x standard to gnu++0x since some of the functions used in the code are only available with gnu++0x on some platforms (e.g. Windows).

Author: abecasis

Makefiles/Makefile.include

@@ -59,7 +59,7 @@ endif
 
 CXX11_AVAIL ?= 1
 
-CPP0X=$(shell if [ X$(CCVERSION) \> X4.3.0 ] ; then echo " -std=c++0x" ; fi)
+CPP0X=$(shell if [ X$(CCVERSION) \> X4.3.0 ] ; then echo " -std=gnu++0x" ; fi)
 
 ifeq ($(CXX11_AVAIL), 0)
 CPP0X=