Added missing username/password attributes to Cube
Merge pull request #21 from rubiojr/add-missing-cube-attributes

Added missing username/password attributes to Cube
Add request to import VMDKs as cubes (Fusion/WS)

The VMX generation code is way too simple, but I can move
forward with this without having to write a proper VMX reading/writing
library.

Added example and some tests.
vmx keys are case insensitive

Make sure we only deal with lowercase case so we don't duplicate them.
loaded VMX keys are lower case