Deprecate v2, remove workarounds, and release v3 of the model.

update all software dependencies

• transition from qs to qs2 (#131);
• update geospatial packages (#132);
• update R version and all project packages (#133);
• update/refactor 'map' package (#134);
• use latest versions of all modules (#135);

more realistic successional dynamics

• relax vegetation parameter forcings;
• improve vegetation parameter estimates (#136);
• simulate additional tree species (#138);
• add vegetation transition plots (#140);

documentation and communication

• improve internal and user-facing model documentation (#139);
• document model v2 and v3 comparisons (i.e., the model itself + implementaiton details);
• document output comparisons between v2 and v3;

miscellaneous

• remove un-needed objects from objects3 going into main sim (#126);
• move uploads etc. to module(s) (#141);