Add a flag to suppress out graphics application

[wookayin]

Followup of #18 --- I think it would be great to have an option to exclude graphics application (i.e. show only CUDA/computing processes). Something like --exclude-graphics

@kapsh What do you think?

[kapsh]

It could be useful for somebody I guess. But I'd suggest another command line arguments handling:

• default (w/o args): list all,
• --type | -t cuda, --type | -t graphics: list only chosen.

[wookayin]

Looks better. Thanks for the suggestion!

[eusoubrasileiro]

thank you all for the future enhancements. Awaiting for them. Congrats on the good work!