Towards 3.1.0-beta3

[cazfi]

3.1.0-beta3 Milestone ("the graphs"): https://osdn.net/projects/freeciv/ticket/milestone/4034
Release ticket for 3.1.0-beta3: https://osdn.net/projects/freeciv/ticket/48105

In addition to fixes targeted to 3.1.0-beta3 as the earliest release, it receives almost all the fixes going to freeciv-3.0.

[cazfi]

First draft of the NEWS: https://www.freeciv.org/wiki/NEWS-3.1.0-beta3

[DamionLedner]

First draft of the NEWS: https://www.freeciv.org/wiki/NEWS-3.1.0-beta3

thanks for sharing