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 ;.
The app could be deployed with cf push, however it was not operatable. We could not cf app, cf scale, and cf delete.

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 ; in the middle or beginning of its name, by using cf curl. Such an app is also unoperatable.

I send this pull request to fix this issue.