make controller-view mapping pluggable

[esumitra]

make the controller-view function mapping pluggable so that different conventions can be used. e.g.,

1. convention where controller function name in "controllers" namespace is mapped to the same name in "views" namespace
2. convention where controller function name of the type resource-controller-method (user-controller-create) is mapped to a view function name of the type resource-view-method (user-view-create)