## Link to GitHub Issue or related Pull Request, if one exists
n/a
## Description of change
To make plugin development easier, add `get_module_info` and
`get_plugin_directory` to deal with common tasks for hooking DLLs and
reading INI files.
Also, add the ability to register for d3d9 present callbacks via
`register_d3d9`, which makes it significantly easier for plugins to draw
things on screen.
## Testing
See sample code.
bicarus