[isabelle-dev] Towards the Isabelle2015 release

[Makarius]

This is the start of the thread for the hot phase.  Until lift-off it can 
take 6-12 weeks.  More precise announcements of events of the preparation 
phase will come within the next few days.

Right now we still have a couple of days of regular changes on the 
repository.  This is also an opportunity to update NEWS and CONTRIBUTORS, 
or to point out missing bits.

As a blind shot at ongoing changes, I will make a pre-test snapshot 
Isabelle2015-RC0, so that more people can get an impression what is 
coming, and hopefully more reports on remaining problems.


 	Makarius