Version 2.0 - Upgrade to separate cell-ECM interactions and PC1.12

This release includes several major upgrades and updates:

• The cell-ECM interaction functionality is now in a separate "module" instead of integrated into AMIGOS-uncoupled.h and `AMIGOS-uncouple.cpp'
  • This enables a user to directly import the cell-ECM interaction and ECM codes and methods into new models, rather than picking through old models
  • The use of this is demonstrated through two new cell-ECM models - a toy model of fibrosis and a toy model of an invasive carcinoma. These new models utilize the density functionality of the ECM and cell-ECM interaction method, complimenting the previously release leader-follower model.
• This release integrates PhysiCell 1.12 - which enables use of the PhysiCell Studio, Rules, and other features of contemporary PhysiCell.

Numerous other small updates are included, such as having one unique config (XML) file per model.

Future enhancements may include further seperation of ECM/cell-ECM functionality out of model source code files, such as the setup_extracellular_matrix function, shell or python scripts for running and processing the simple and toy models, and creating make file rules to enable a more PhysiCell like way of storing and building models.