@AlanHK: Patches welcome. If someone wanted to port the Sigil C++ code that updates every link in every file, manifest, index, toc, guide-reference, footnote, and css url in every epub to Python to be used in this one Sigil plugin, I'm sure adding it to this one would be considered. But for most, porting something that complicated and invasive is not something that lends itself well for use in individual plugins. Especially when it would have to be kept in sync with any future C++ bug-fixes/behavior-changes for the rest of time.
But if someone were to volunteer their time to mirror and maintain Sigil's inherent file renaming, and link-parsing/updating routines in a safe, reusable Python module that could be added to Sigil's plugin framework, I'm sure many plugin devs would be appreciative of the contribution. It would have to be limited to input/output plugins, though, since there is no file renaming ability for Sigil edit plugins.
Hell of a lot of work to undertake for someone, though. Just to take care of something someone could easily remedy by RTFM and then jotting down their own pre-conversion checklist.
