add REST documentation for uservoice module
remove server from REST endpoint keys
add REST documentation for discussions module
add common models from discussions module
move Tenant model to common models
move tenant model to common models
Merge branch 'restdoc-discussions' of https://github.com/sathomas/Hilary into restdocs
Merge branch 'restdoc-tenants' of https://github.com/sathomas/Hilary into restdocs
Merge branch 'restdoc-uservoice' of https://github.com/sathomas/Hilary into restdocs
Merge branch 'restdoc-util' of https://github.com/sathomas/Hilary into restdocs