Fixed parameters resolution of generated factories

The previous [commit](https://github.com/nette/di/commit/a1f48d002b9a67d2c23051576a2a62dc67e109cf) doesn't seem to work as expected in all cases (http://forum.nette.org/cs/20601-generovane-tovarnicky-s-parametry). Of course I will add more tests for this.