Trivial git script fixups

Fix permissions, and add trivial "reset" and "add" scripts.

The "reset" script just resets the index back to head, while the "add"
script is just a crutch for people used to do "cvs add".

git-diff-script

@@ -3,13 +3,13 @@ rev=($(git-rev-parse --revs-only "$@"))
 flags=($(git-rev-parse --no-revs "$@"))
 case "${#rev[*]}" in
 0)
-	git-diff-files -p "$@";;
+	git-diff-files -p -C "$@";;
 1)
-	git-diff-cache -p "$@";;
+	git-diff-cache -p -C "$@";;
 2)
 	begin=$(echo "${rev[1]}" | tr -d '^')
 	end="${rev[0]}"
-	git-diff-tree -p $flags $begin $end;;
+	git-diff-tree -p -C $flags $begin $end;;
 *)
 	echo "I don't understand"
 	exit 1;;