What's the story behind pyAltFCFGMerge ?

[Matúš Kukan]

Currently in filter/Configuration_filter.mk we use pyAltFCFGMerge or
FCFGMerge.jar depending on whether we build with java.
Do they produce the same result ?
If no, how come there are no bugs or something ?
It yes, can we remove FCFGMerge.jar and use pyAltFCFGMerge all the time ?

Thanks,
Matus