Aegisub example: try harder to load library.
Allow user to pass fonts.conf path to assi_init.
Reorganize functions to match header order.
Example: replace logRect with dumpRect.
Example: store ASSI_State between runs.
Example: embellish a few comments.
Example: update C function prototypes.
Add assi_setFontDir.
Don't exit loop if there is nothing to render one time.
Attempt to make use of libass caching.
Fix bounds calculation.

There were a bunch of problems with the previous bounds calculation
algorithm.

It didn't check to see if the x/y offset had changed after the first
image was processed.

It didn't use absolute coordinates to check for the width and height,
so they could theoretically come out wrong.

It didn't perform comparison when setting the height.