Nwe feature: user actions

[ Feature description ]

We want to allow account provisionning, and this could be accompanied
by information about how to setup the new created user account.

For example, we expect that if a workspace implements an authentication
for a group of people, these are added to a group having access to the
workspace.

Another possibility would be to grant a precise permission.

[ Feature implementation ]

• New abstract class UserAction
• Two actions matching the behavior described below:
  • AddToGroupUserAction
  • GivePermissionUserAction

[ Core libraries new methods and function ]

• User::isMemberOfGroup(UserGroup $group) Determines if the user is a member of the specified group

• User::addToGroup (UserGroup $group, $isAdmin = false) Adds user to the specified group

• User::setPermission ($resourceType, $resourceId, $permissionName, , $permissionFlag = 1) Sets user permission

• static UserGroup::fromCode ($code) Loads the specified user group from code

• get_resource_id ($resource_type, $identifier) Gets the resource ID from an identifier This allows to describe resources by codenames, not by numeric id.