massive commit: add ability to iterate over organizations and filter workspaces, and easily generate helper classes.  Also, implement server-based authentication in an easy way

for example:

$myorganizations = Chiara\PodioOrganization::mine();
foreach ($myorganizations['unledu']->workspaces->matching('^SOM:
Chamber Music') as $space) {
    $ret = $space->generateClasses(__DIR__ . '/modeltest',
'SOM\Models');
}