In the code:
* general plugin API calls (in plugins/write order),
* VCS plugin API calls (in plugins/write order), then
* internal support routines (in alphabetical order).
In the tests:
* general meta-behavior (in no particular order, yet),
* general plugin API calls (in plugins/write order),
* VCS plugin API calls (in plugins/write order), then
* internal support routines (in semi-logical order).