Register GPU formats first (even before core formats - this is experimental)
Revert "Mask mode bugfix"

This reverts commit e3c44cb2184b907af00933a87e755c7b25ce95fc.

Revert "Add usage output for mask mode."

This reverts commit 869a866266e656aaff7dc6777203cba6811a1b06.

Revert "Bug fixes for mask mode."

This reverts commit a8d90c0037e5ebac75f87f56c3e5e00f60ac8459.

Revert "Add mask mode"

This reverts commit 25aeead37e7f997ef193817ff6cdfd3439c31958.