Revision to Succession Library (v7)

[Robert Scheller]

In March 2019, the Technical Advisory Committee approved the following:

* A new Succession library (v7) was created which does not include the Initial Community Library (ICL) or references to the ICL.

* A new and separate ICL which can be modified for different situations without affecting any other extensions except succession extensions was created and given its own repository.

* Age-only and Biomass and NECN and PnET succession extensions were updated to reference succession library v7.  

* The harvest extensions were recompiled with succession library v7 referenced, otherwise no additional changes.  No other extensions access the succession library.

The reasons in brief:  The no-spin-up used by NECN and now PnET required a tweaked version of the succession / initial community library.  Issues occurred during planting as the harvest extensions use the standard succession library (v6).

The consequences of NOT changing the succession library v6 configuration:

* NECN and PnET cannot use planting