Utilities/Release: Build Linux and OS X binaries as C++14

The toolchains we use to build on these platforms support it.

Utilities/Release/linux64_release.cmake

@@ -21,7 +21,7 @@ set(qt_xcb_libs
 set(INITIAL_CACHE "
 CMAKE_BUILD_TYPE:STRING=Release
 CMAKE_C_STANDARD:STRING=11
-CMAKE_CXX_STANDARD:STRING=11
+CMAKE_CXX_STANDARD:STRING=14
 CMAKE_C_FLAGS:STRING=-D_POSIX_C_SOURCE=199506L -D_POSIX_SOURCE=1 -D_SVID_SOURCE=1 -D_BSD_SOURCE=1
 CMAKE_EXE_LINKER_FLAGS:STRING=-static-libstdc++ -static-libgcc
 CURSES_LIBRARY:FILEPATH=/home/kitware/ncurses-5.9/lib/libncurses.a

Utilities/Release/osx_release.cmake

@@ -14,7 +14,7 @@ set(CXXFLAGS "-stdlib=libc++")
 set(INITIAL_CACHE "
 CMAKE_BUILD_TYPE:STRING=Release
 CMAKE_C_STANDARD:STRING=11
-CMAKE_CXX_STANDARD:STRING=11
+CMAKE_CXX_STANDARD:STRING=14
 CMAKE_OSX_ARCHITECTURES:STRING=x86_64
 CMAKE_OSX_DEPLOYMENT_TARGET:STRING=10.7
 CMAKE_SKIP_BOOTSTRAP_TEST:STRING=TRUE