Free Windows library handles when we free_all in a module
Tor frees most resources on shutdown, using module *_free_all functions.
But we don't free Windows library handles.
Here's what we'd need to do:
- write a generic function for freeing Windows library handles in winlib.c
- call that function to free all the library handles, after we've finished using functions from those libraries
This change would only affect compat_time.c and ntmain.c. They don't currenly have *_free_all functions.
This is low-priority, because Windows libraries are reference-counted. And the two libraries that tor uses are needed for the life of the process.