PAV-415 Improve Magpie UI

[fmigneault]

Changes

• replaces text input by combobox for services' resources according to their respectively allowed resources (ie: only file/directory selectable within thredds, only workspace for WMS)
• removes possibility to add children resources in treeview for file
• replace radio buttons in pages add_user, add_service and login by combobox control
• make input forms with comboboxes of same size as input text
• change buttons side-by-side for view_users, view_groups and view_services
• make red button for delete operations
• make disabled grey button for not permitted operations according to context (add_child / delete)
• dynamically change home page buttons position according to available screen width

Extra

• made code cleanup according to multiple found deprecation warnings
• fixed some make / compile issues
• fixed error resulting from invalid ServiceWFS class inheritance

[dbyrns]