This release (the first in a long time) pulls in all upstream changes in Lua 5.3.3 (5.3.4 had zero changes affecting pattern matching), including a fix for a bug involving gmatch and coroutines and removal of non-linear complexity limits.
As a side effect of bringing in these changes, the behavior of gmatch and gsub (including the table-return versions of those functions provided by this module) has changed with regard to empty matches. While I disagree with this change being made in a bugfix release, the Lua team is correct that it was technically undefined behavior, so is valid in a bugfix release.
Under the hood, the CI testing has been significantly improved, including the introduction of AppVeyor for testing on Windows. Finally, a number of unnecessary C standard library header includes have been removed from the main source file.