Specify features

[W4RH4WK]

Apparently clippy does no longer set the clippy feature flag automatically due to some incompatibilities. I'd like to request an entry in the options menu which lets me specify features passed to the cargo command (space or comma separated list would suffice).
#30 may be related to this.

[White-Oak]

Yes, gets really hard to lint, when writing code for non-default targets, but specifying features is certainly possible, I'll make a PR for it.

[W4RH4WK]

I'd lint the non-default targets manually on the commandline. Thanks for your incoming PR.

[White-Oak]

Saying non-default targets I really meant non-default features, sorry for misunderstandment.