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/Proxy.hs

@@ -17,10 +17,10 @@ import qualified Git.Sha
 import qualified Git.Ref
 import qualified Git.Branch
 
-cmd :: [Command]
-cmd = [notBareRepo $
+cmd :: Command
+cmd = notBareRepo $
 	command "proxy" ("-- git command") seek
-		SectionPlumbing "safely bypass direct mode guard"]
+		SectionPlumbing "safely bypass direct mode guard"
 
 seek :: CommandSeek
 seek = withWords start