Adding return values to notmuch_database_close and
notmuch_database_destroy may require bumping the soname.
# the library interface, (such as the deletion of an API or a major
# semantic change that breaks formerly functioning code).
#
-LIBNOTMUCH_VERSION_MAJOR = 3
+LIBNOTMUCH_VERSION_MAJOR = 4
# The minor version of the library interface. This should be incremented at
# the time of release for any additions to the library interface,