Make --version less verbose

When calling "jspm --version" only the version number and the information if jspm is running against a global or local install gets now printed.

I've also removed the initial empty line that gets printed within the lib/ui.js when ui.log() gets called for the first time in order to make the console output look more like `npm -v` or `bower -v`

```bash
$ npm -v
2.1.11
$ bower -v
1.3.12
$ jspm -v
0.9.0
Running against local jspm install.
```

I've tested also other commands to see if the console output looks strange if this initial empty line is missing but so far everything looked ok for me.

closes #300