started converting to use optparse-applicative

This is a work in progress. It compiles and is able to do basic command
dispatch, including git autocorrection, while using optparse-applicative
for the core commandline parsing.

* Many commands are temporarily disabled before conversion.
* Options are not wired in yet.
* cmdnorepo actions don't work yet.

Also, removed the [Command] list, which was only used in one place.

Command/ResolveMerge.hs

@@ -14,9 +14,9 @@ import Git.Sha
 import qualified Git.Branch
 import Annex.AutoMerge
 
-cmd :: [Command]
-cmd = [command "resolvemerge" paramNothing seek SectionPlumbing
-	"resolve merge conflicts"]
+cmd :: Command
+cmd = command "resolvemerge" paramNothing seek SectionPlumbing
+	"resolve merge conflicts"
 
 seek :: CommandSeek
 seek = withNothing start