Description: The aimosLogin branch carries the leafs for logging in as a specific user.

As above-mentioned access to the branch aimosLogin is only permitted with SNMP
community set to a value published by aimosCommunity.

Login process is performed by the following actions:
. Get SNMP community string from aimosCommunity using public as community name.
  Use this community name in further SNMP requests.
. Set the user name in aimosLoginUserName (use the new community name!)
. Set the corresponding password in aimosLoginPassword expect in the case of the
  first login after software installation.
  In that case a text in the following format has to be used as password:
         nnnnnn xxxx xxxx xxxx xxxx xxxx aaaaaaa
   where n is the OrgID
         x is the license key
         a is the license extra data (may be omitted)
. Set aimosLoginState to connected(1).
. Check the current aimosLoginState.
  . If login was successful, then it is set to connected(1) state.
  . If the password is wrong, then it is set to refused(2) state.
  . If passwordExpired(4) is returned, the password has expired.

Password expiration
===================
All passwords are valid for an amount of days. This period of time is specified
in aimosPasswordExpirationPeriod. If a password was unchanged for more than the
specified number of days, then the password expires. Existing Sessions are not
affected by the password expiration.

When a password has expired, no login can be made for the corresponding user
account, until the user has defined a new password.

The new password has to be assigned to aimosLoginPassword in order to complete
the login process. If the new password is permissible then
. this password is stored in aimosUserPassword and has to be used in the future
. and aimosLoginState gets connected(1).

The default password (start) is expired by default. I.e., if the default password
is used for login, the user needs to advise a new password as mentioned above.

Due to the
. minimum password length requirements (aimosMinPasswordLength)
. or the reusability of passwords (aimosPasswordReuseCounter)
. as well as the requirements on password security (aimosPasswordStandard)
it may be possible, that the new password is not acceptable by the A.I.M.O.S. SNMP
Agent. In that case, the password remains expired and the user is required to
. devise another password and repeat this procedure until aimosLoginState gets
  connected(1)
. or cancel the login process by setting aimosLoginState to disconnected(0)

Logout
======
Set aimosLoginState to disconnected(0) in order to log out. After log out the
community name is invalid and therefore aimosLoginState gets canceled(3).
If you need to log in again, then you have to request for a new community name
by the steps described above.