ggplot2 3.4.1

This is a small release focusing on fixing regressions in the 3.4.0 release
and minor polishes.

Breaking changes

• The computed variable y in stat_ecdf() has been superseded by ecdf to
  prevent incorrect scale transformations (@teunbrand, #5113 and #5112).

New features

• Added scale_linewidth_manual() and scale_linewidth_identity() to support
  the linewidth aesthetic (@teunbrand, #5050).

• ggsave() warns when multiple filenames are given, and only writes to the
  first file (@teunbrand, #5114).

Bug fixes

• Fixed a regression in geom_hex() where aesthetics were replicated across
  bins (@thomasp85, #5037 and #5044).

• Using two ordered factors as facetting variables in
  facet_grid(..., as.table = FALSE) now throws a warning instead of an
  error (@teunbrand, #5109).

• Fixed misbehaviour of draw_key_boxplot() and draw_key_crossbar() with
  skewed key aspect ratio (@teunbrand, #5082).

• Fixed spurious warning when weight aesthetic was used in stat_smooth()
  (@teunbrand based on @clauswilke's suggestion, #5053).

• The lwd alias is now correctly replaced by linewidth instead of size
  (@teunbrand based on @clauswilke's suggestion #5051).

• Fixed a regression in Coord$train_panel_guides() where names of guides were
  dropped (@maxsutton, #5063).

In binned scales:

• Automatic breaks should no longer be out-of-bounds, and automatic limits are
  adjusted to include breaks (@teunbrand, #5082).

• Zero-range limits no longer throw an error and are treated akin to continuous
  scales with zero-range limits (@teunbrand, #5066).

• The trans = "date" and trans = "time" transformations were made compatible
  (@teunbrand, #4217).