v2.1.2 keep up with Fugitive changes

Fixed

• Made merginal commands global, not buffer-local, because Fugutive no longer fires the signals Merginal depended on.
• Changed fugitive#detect to FugitiveDetect.
• Made pS push with --force-with-lease instead of just --force. Yes, this is a fix. No this is not a breaking change. If this breaks your workflow then your workflow was broken to begin with.
• Made all the mappings <nowait>.