remove check for cyclic dependencies from runner. i guess it just never happens. added a simple assert.
remove check for cyclic dependencies from runner. i guess it just never happens. added a simple assert.

--HG--
extra : convert_revision : schettino72-20101218210344-30dissxjqpnskmie

swayf/doit,okin/doit,okin/doit,okin/doit,swayf/doit,swayf/doit