chuck @1.4.0.1: error: use of undeclared identifier 'nullptr'

[ryandesign (Ryan Carsten Schmidt)]

​https://build.macports.org/builders/ports-10.7_x86_64-builder/builds/153572/steps/install-port/logs/stdio

/usr/bin/clang++ -I. -Ilo -O3 -D__MACOSX_CORE__   -arch x86_64 -c chuck_dl.cpp -o chuck_dl.o

chuck_dl.cpp:1036:47: error: use of undeclared identifier 'nullptr'
    hook->m_carrier->chuck->setMainThreadHook(nullptr);
                                              ^
1 error generated.

Fixing this requires setting configure.cxx_standard 2011, adding configure.cxxflags-append -std=c++11, and actually passing CFLAGS, CPPFLAGS, CXXFLAGS, LDFLAGS to the build system; this last can be accomplished through correct use of the makefile portgroup. See comment:ticket:49741:1 for prior discussion.