Hotfix: return parsed options if argument parsing failed

This fixes [#373](https://github.com/jbenet/go-ipfs/issues/373).

The reason it was failing is that Parse() func even when `req` instance was intialized correctly it was not returned if there was an argument parsing exception. 

`Request.options` contains mention of `--help` flag (within `request.options` as `map[string]string{`help`:"",}`) that is used to check if the help option was called.