Make ENCOUNTER return null OrbitInfo with default values.

Somewhat addresses #243 but the real issue that needs to be fixed is eluding me for now.
```
if encounter == "Mun" { awesome things }.
```
In the above example i believe kOS doesn't think value 2 is a string. A simple workaround is to declare a variable and compare that.
```
set trgt to "Mun".
if encounter == trgt { magic things }.
```
monodevel and it's indenting RAGE