unar: fix description
unar: fix description

unar is the command line version of the popular OS X unarchiving app The
Unarchiver. It supports dozens of formats (see full list at
https://unarchiver.c3.cx/formats). Definitely not limited to RAR. In
fact, supporting multiple formats is the main reason why unar is
insteresting when there are already canonical tools for each format,
e.g., 7z, gunzip, tar, unrar, unxz, unzip, etc.

Also fixed two minor audit problems along the way.

Closes #355.
filcab/homebrew-core,adamliter/homebrew-core,git-lfs/homebrew-core,andyjeffries/homebrew-core,BrewTestBot/homebrew-core,kuahyeow/homebrew-core,bcg62/homebrew-core,nandub/homebrew-core,lasote/homebrew-core,bigbes/homebrew-core,lemzwerg/homebrew-core,nbari/homebrew-core,makigumo/homebrew-core,straxhaber/homebrew-core,nandub/homebrew-core,Linuxbrew/homebrew-core,cblecker/homebrew-core,DomT4/homebrew-core,rwhogg/homebrew-core,stgraber/homebrew-core,Homebrew/homebrew-core,mbcoguno/homebrew-core,aabdnn/homebrew-core,mvitz/homebrew-core,spaam/homebrew-core,fvioz/homebrew-core,filcab/homebrew-core,bfontaine/homebrew-core,chrisfinazzo/homebrew-core,smessmer/homebrew-core,mfikes/homebrew-core,adam-moss/homebrew-core,zyedidia/homebrew-core,LinuxbrewTestBot/homebrew-core,kunickiaj/homebrew-core,bcg62/homebrew-core,straxhaber/homebrew-core,sjackman/homebrew-core,ylluminarious/homebrew-core,gserra-olx/homebrew-core,smessmer/homebrew-core,j-bennet/homebrew-core,Linuxbrew/homebrew-core,jabenninghoff/homebrew-core,battlemidget/homebrew-core,passerbyid/homebrew-core,reelsense/homebrew-core,wolffaxn/homebrew-core,mahori/homebrew-core,forevergenin/homebrew-core,maxim-belkin/homebrew-core,adam-moss/homebrew-core,jvehent/homebrew-core,bfontaine/homebrew-core,grhawk/homebrew-core,cblecker/homebrew-core,stgraber/homebrew-core,grhawk/homebrew-core,forevergenin/homebrew-core,sdorra/homebrew-core,aabdnn/homebrew-core,mvitz/homebrew-core,ShivaHuang/homebrew-core,lembacon/homebrew-core,aren55555/homebrew-core,jvillard/homebrew-core,gserra-olx/homebrew-core,uyjulian/homebrew-core,mahori/homebrew-core,phusion/homebrew-core,fvioz/homebrew-core,jdubois/homebrew-core,phusion/homebrew-core,Moisan/homebrew-core,zmwangx/homebrew-core,JCount/homebrew-core,FinalDes/homebrew-core,mbcoguno/homebrew-core,zmwangx/homebrew-core,aren55555/homebrew-core,Moisan/homebrew-core,JCount/homebrew-core,ilovezfs/homebrew-core,uyjulian/homebrew-core,battlemidget/homebrew-core,wolffaxn/homebrew-core,zyedidia/homebrew-core,mfikes/homebrew-core,git-lfs/homebrew-core,jvillard/homebrew-core,passerbyid/homebrew-core,robohack/homebrew-core,jdubois/homebrew-core,maxim-belkin/homebrew-core,adamliter/homebrew-core,kuahyeow/homebrew-core,edporras/homebrew-core,lemzwerg/homebrew-core,andyjeffries/homebrew-core,jvehent/homebrew-core,ylluminarious/homebrew-core,dsXLII/homebrew-core,BrewTestBot/homebrew-core,nbari/homebrew-core,moderndeveloperllc/homebrew-core,dsXLII/homebrew-core,reelsense/homebrew-core,robohack/homebrew-core,tkoenig/homebrew-core,sjackman/homebrew-core,mvitz/homebrew-core,mvbattista/homebrew-core,ilovezfs/homebrew-core,spaam/homebrew-core,chrisfinazzo/homebrew-core,jabenninghoff/homebrew-core,mbcoguno/homebrew-core,DomT4/homebrew-core,FinalDes/homebrew-core,ShivaHuang/homebrew-core,jvillard/homebrew-core,tkoenig/homebrew-core,kunickiaj/homebrew-core,j-bennet/homebrew-core,mvbattista/homebrew-core,Homebrew/homebrew-core,bcg62/homebrew-core,makigumo/homebrew-core,lembacon/homebrew-core,bigbes/homebrew-core,LinuxbrewTestBot/homebrew-core,lasote/homebrew-core,lembacon/homebrew-core,jdubois/homebrew-core,moderndeveloperllc/homebrew-core,edporras/homebrew-core,wolffaxn/homebrew-core,rwhogg/homebrew-core,sdorra/homebrew-core