pages: dynamic set up is now done just before prepare_render call: dynamic set up is not done at the beginning of the page workflow anymore because dynamic method should not be used during parse_url and page workflow may switch in case of redirection.

try:
    from common.constants import Const as C
except ImportError:
    pass # import doesn't work at this stage with pyjamas
else:
    __version__ = C.APP_VERSION