[Bf-committers] On compatibility break

[Antony Riakiotakis]

Hi, so far we have been changing the user preferences folders slightly
prior to release. However, and since we are planning to break compatibility
on 2.70 series it might be a good idea to change the preferences folder as
soon as we enter bcon1.

This could help users having both stable/master editions without one
causing hickups to the configuration of the other.