VMM{,/cli}/Handler: adjusted user* methods to the changes in Account.
All user methods was renamed from userAction() to user_action().
Added missing docstrings.
.. Substitutions in section 1
.. |account.disk_usage| replace:: `account.disk_usage`
.. _account.disk_usage: vmm.cfg.5#account-disk-usage
.. |domain.force_deletion| replace:: `domain.force_deletion`
.. _domain.force_deletion: vmm.cfg.5#domain-force-deletion
.. |misc.transport| replace:: `misc.transport`
.. _misc.transport: vmm.cfg.5#misc-transport
.. #EOF