Added CSV import to the master branch

Here is the CSV import as mentioned in the thread: https://bitcointalk.org/index.php?topic=100502.620

It can accept either a CSV file or CSV entered into a text box. The rough format is:

```
"ADDRESS", 0.12345
"ADDRESS", 0.12314
```

No headers processed.

It will create the unsigned transaction (with default fees) and use the transaction signing dialog to permit signature signing.