C++ version issue with rootv6.26

[rcoleman48]

I ran into when trying to compile NTuple with rootv6.26.00 since it requires support for C++14 or higher. There is a work around by editting the Makefile: if you change line 27
CXXFLAGS = -std=gnu++0x -pedantic -Wall -Wno-long-long -g -O3
to
CXXFLAGS = -std=c++14 -pedantic -Wall -Wno-long-long -g -O3

I am not going to push these changes since this will likely cause errors for anyone using an earlier version of root.