Vidalia does not allow edited torrc to contain multiple lines with different option values

Vidalia doesn't allow the user-edited torrc to contain multiple lines with different option values.

To reproduce:

1. Settings -> Advanced -> Edit current torrc
2. Enter multiple SocksPort or MapAddress lines
3. Click Ok
4. Edit current torrc again

What you expect to see:

1. Multiple lines specifying different SocksPort or MapAddress options should appear

What really happens:

1. Vidalia parses the torrc to only contain one SocksPort or MapAddress lines