Fixes fixed Issue #160.

The method checking for correct direction of incoming or outgoing
features in flows did not take into account the feature group direction
if the feature was an element of a feature group.
Fixed Fixes Issue #161.
In flow implementation we were setting doReverse even when the
connection is not bi-directional. 
We are now separetely checking for biDirectional and only then check the
condition and if necessary set the flag.