Fix name validation

Prohibit ';' in name of app / space / organization / app security group,
because the character is used as the separator in query.

We have happend to a problem with an app whose name ends with a semicolon <code>;</code>.
The app could be deployed with <code>cf push</code>, however it was not operatable. We could not <code>cf app</code>, <code>cf scale</code>, and <code>cf delete</code>.

The original cause is here:
https://github.com/tamac-io/cloud_controller_ng/blob/262c4fd7723cd04b28d2b6bafeca5b1800a39e73/lib/vcap/rest_api/query.rb#L76
```
  segments = query.split(";")
```

Query-enabled CC APIs use this method. Because CLI uses query heavily (especially to get guid for human readable name), many operations fail.

Actually, we can push an app with <code>;</code> in the middle or beginning of its name, by using <code>cf curl</code>. Such an app is also unoperatable.

I send this pull request to fix this issue.