convert_imageset now uses gflags; optional arguments can be positioned
arbitrarily now
Handles gflags's change of namespace
Fix lint errors
Reordering of header includes for convert_imageset.cpp
Use gflags to show help when the arguments not correct
create_imagenet.sh updated to new syntax
Merge pull request #857 from netheril96/gflags

Use gflags to parse command line arguments for convert_imageset