Support for theming in PHP templates has been dropped.
True theming should support theme inheritance, e.g. mytheme <- table <- default.
Currently, the Templating component does not support such inheritance. As the
only purpose of the themes so far was to style field groups with tables or
divs, and because automatic rendering of field groups/forms through the render()
method is discouraged and only recommended for rapid prototyping, themes are
dropped for now.
For existing Symfony2 applications, references to Symfony\Framework are found
in the main Kernel class (registerBundles() and registerBundleDirs()), and in
all Controller classes. You also need to change the console script.
