patchgit-svn: delay term initialization

> On my Debian 7 system, this gives annoying warnings when the output
> of "git svn" commands are redirected:
>
>     Unable to get Terminal Size. The TIOCGWINSZ ioctl didn't work.
>     The COLUMNS and LINES environment variables didn't work. The
>     resize program didn't work.
>
> Signed-off-by: Eric Wong <normalperson@yhbt.net>
> ---
>  Also, manually tested to ensure dcommit --interactive works.

>
>  git-svn.perl | 18 +++++++++++-------
>  1 file changed, 11 insertions(+), 7 deletions(-)
>
> diff --git a/git-svn.perl b/git-svn.perl
> index 40565cd..ce0d7e1 100755
> --- a/git-svn.perl
> +++ b/git-svn.perl
> @@ -306,13 +306,16 @@ sub readline {
>  }
>  package main;
>  
> -my $term = eval {
> -	$ENV{"GIT_SVN_NOTTY"}
> -		? new Term::ReadLine 'git-svn', \*STDIN, \*STDOUT
> -		: new Term::ReadLine 'git-svn';
> -};
> -if ($@) {
> -	$term = new FakeTerm "$@: going non-interactive";
> +my $term;
> +sub term_init {
> +	$term = eval {
> +		$ENV{"GIT_SVN_NOTTY"}
> +			? new Term::ReadLine 'git-svn', \*STDIN, \*STDOUT
> +			: new Term::ReadLine 'git-svn';
> +	};
> +	if ($@) {
> +		$term = new FakeTerm "$@: going non-interactive";
> +	}
>  }
>  
>  my $cmd;
> @@ -424,6 +427,7 @@ sub ask {
>  	my $default = $arg{default};
>  	my $resp;
>  	my $i = 0;
> +	term_init() unless $term;
>  
>  	if ( !( defined($term->IN)
>              && defined( fileno($term->IN) )