The following pool configuration would allow a pool to be aliased in POST
requests as 'centos-6-x86_64', 'centos-6-amd64', or 'centos-6-64':
````yaml
- name: 'centos-6-x86_64'
alias: [ 'centos-6-amd64', 'centos-6-64' ]
template: 'templates/centos-6-x86_64'
folder: 'vmpooler/centos-6-x86_64'
datastore: 'instance1'
size: 5
````
The 'alias' configuration can be either a string or an array.
Note that even when requesting an alias, the pool's 'name' is returned in
the JSON response:
````
$ curl -d '{"centos-6-64":"1"}' --url vmpooler/api/v1/vm
````
````json
{
"ok": true,
"centos-6-x86_64": {
"hostname": "cuna2qeahwlzji7"
},
"domain": "company.com"
}
````
Prior to this commit, several pieces of vmpooler performed configuration
and initialization steps within 'initialize'. This made it difficult to
pass in mock objects for testing purposes.
This commit performs a single configuration and passes the results to
the various pieces of vmpooler.
