Bump version to 3.0.0

We need a major bump as the bidirectional API changed since the last
release.

There need to be some refinements to some of the implementations for
conformance, but overall it works reliably.

Signed-off-by: Laslo Hunhold <dev@frign.de>

Makefile

diff --git a/Makefile b/Makefile
index 2be575b..0850708 100644
--- a/Makefile
+++ b/Makefile
@@ -3,9 +3,9 @@
 .POSIX:
 .SUFFIXES:
 
-VERSION_MAJOR = 2
+VERSION_MAJOR = 3
 VERSION_MINOR = 0
-VERSION_PATCH = 1
+VERSION_PATCH = 0
 UNICODE_VERSION = 17.0.0
 MAN_DATE = 2022-10-06