Shea told me composableDerivation is hard to understand.

Thus comment it and why it was written long time ago until it'll get replaced piecewise.
Updated to mutt-1.5.23
httpie: Update -> 0.8.0

Signed-off-by: Ricky Elrod <ricky@elrod.me>
Merge pull request #2583 from CodeBlock/update-httpie

httpie: Update -> 0.8.0
Merge pull request #2506 from ikervagyok/mutt

Updated to mutt-1.5.23
Merge pull request #2454 from MarcWeber/submit/document-composableDerivation

Shea told me composableDerivation is hard to understand.
fetchFromGitHub: Use .tar.gz instead of .zip

Also clean up the name attribute of fetchzip derivations a bit.
When auto-formatting ext devices, use the -F flag to make it work with unpartioned disks