Homebrew need parallel install support at least for downloads

[ssbarnea]

As there were multiple issues that were closed, maybe it is time to create discussion thread for parallel downloading and eventually even installing of casks.

Due to its serial behavior, brew is one of the slowest package managers and we should try to address this in the future, even if that is not very easy. At least the download part should be ok to happen in background.

• [Feature Request] Parallel downloads on upgrade brew#1865
• Support to install/update/upgrade apps concurrently brew#11363
• Fully parallel downloads on install brew#12489
• Parallel downloads brew#13064
• Feature request: Parallel downloads homebrew-cask#21992

[SMillerDev]

Go ahead

[carlocab]

This is being tracked at Homebrew/brew#18278.