[1119127] rhqctl to prompt for rhqadmin password, rather than using hard-coded default
We no longer support the default rhqadmin/rhqadmin user/password superuser
combination.  The rhqadmin user still exists but the password must be
set by the user. The new rhq.autoinstall.server.admin.password property
must be set in rhq-server.properties.  If not set the 'rhqctl install'
command will prompt for a password and update rhq-server.properties with
the encrypted value.  Additionally, the rhq-encode-password.sh|bat machanism has been
enhanced to allow the user to generate the value.

Cherry-pick of master: 8ae6185692d37150491457ea9207be156a67ddc2

Note that dev containers are unchanged and automatically provide rhqadmin/rhqadmin.