Abiquo cleanup: round one

This is the first round for a major Abiquo cleanup.

The Abiquo provider was huge, had lots of features that were out of the scope of jclouds, and was obsolete. Having such an amount of features made it very difficult to keep the provider up to date, so a major cleanup was required.

This PR leaves only the project skeleton and the authentication filters. Follow-up PRs will start adding a new domain model using google auto and will implement what is needed for the compute abstraction. This way the provider will have only the features that make sense in jclouds and we'll be in a better position to promote and maintain it.

/cc @adriancole (can you beat the number of deletions? :-))