Analysis Situs allows for extensions via Tcl plugins. On startup, it checks the contents of asi-plugins
directory located in the working (installation) directory of the software. Analysis Situs attempts to
load all dynamic libraries it finds in that directory. For being a valid plugin, a dynamic library should
satisfy specific rules. Analysis Situs tries to call a function named PLUGINFACTORY.
If no such function exists, the corresponding candidate library is skipped with an error message.