Fix rhbz#643488: inconsistent lower/upper casing
    
    ... in dialog titles and a few button captions triggering these dialogs
    
    - list of changes in "section: add dialog title" format:
    
    ---(dialog titles)---
    
    Clusters:                      Add an Existing Cluster
                                   -> Add Existing Cluster
    
    Nodes:                         Add nodes to this cluster
                                   -> Add Nodes To Cluster
    
    Services:                      Add a service
                                   -> Add Service To Cluster
    
    Resources:                     Add a resource
                                   -> Add Resource To Cluster
    
    Failover Domains:              Create a Failover Domain
                                   -> Add Failover Domain To Cluster
    
    Fence Devices:                 Add a Fence Instance
                                   -> Add Fence Device (Instance)
                                   (note: this is shared, thus this title)
    
    Nodes--Add a Fence Method:     Create a Fence Method
                                   -> Add Fence Method To Node
    
    Nodes--Add a Fence Instance:   Add a Fence Instance
                                   -> Add Fence Device (Instance)
                                   (note: this is shared, thus this title)
    
    Service--Add a resource:       Add a resource to this service
                                   -> Add Resource To Service
    
    Service--Add a child resource: Add a resource to this service
                                   -> Add Resource To Service
    
    Clusters:                      Create a Cluster
                                   -> Create New Cluster
    
    ---(button captions)---
    
    Nodes:                         Add a Fence Method
                                   -> Add Fence Method
    
                                   Add a Fence Instance
                                   -> Add Fence Instance
    
    Resources:                     Add a child resource
                                   -> Add Child Resource
    
    Services:                      Add a resource
                                   -> Add Resource
    
    ---
    
    notes:
      - "Add a Fence Device" dialog definition not used and hence removed
      - also "Add a User" changed to "Add User" but this is not currently
        exposed anywhere