* \use_qimage
This is no longer necessary due to the rewrite of the painter.
+* \use_pixmap_cacheqimage
+ There is no evidence that this painting mode was useful anymore.
+
* \date_insert_format
The function date-insert has been removed and superseded by info-insert date.
The latter does not need a pref value anymore.
!!Caveats when upgrading from earlier versions to 2.4.x
+* Autotools monolithic build option for building LyX binaries was removed,
+ for compilation speedup use parallel building on multiple cores instead.
!! If upgrading from a LyX version before 2.3.0