vcsh: Create the local branch during clone

This will create and checkout a local branch named after the upstream
branch. It will also gracefully behave for the default `master' branch
and consistently show the same message:

Switched to a new branch '$VCSH_BRANCH'

vcsh

@@ -148,6 +148,7 @@ clone() {
 	git remote add origin "$GIT_REMOTE"
 	git config branch."$VCSH_BRANCH".remote origin
 	git config branch."$VCSH_BRANCH".merge  refs/heads/"$VCSH_BRANCH"
+	git checkout -b $VCSH_BRANCH
 	if [ $(git ls-remote origin "$VCSH_BRANCH" 2> /dev/null | wc -l ) -lt 1 ]; then
 		info "remote is empty, not merging anything"
 		exit