Issue #245: Unclear error for account name starting with number: unexpected COLON (blais/beancount)

[Martin Michlmayr]

New issue 245: Unclear error for account name starting with number: unexpected COLON
https://bitbucket.org/blais/beancount/issues/245/unclear-error-for-account-name-starting

Martin Michlmayr:

With:

```
Assets:Vouchers:99Ranch
```

I get:

```
syntax error, unexpected COLON, expecting EOL or COMMENT
```

I think this is a big unclear. It should complain about the digits, not the colon.