checksums.xxhash: adding xxHash checksum implementation.
checksums.murmur: remove code duplication.
checksums.md5: remove extra "32 bits".
random: simplify using bitwise operations.
checksums.xxhash: cleanup, faster.
checksums.internet: simplify.
sequences.extras: adding replicate-into.
io.files.info.unix.linux: cleanup stack effects.
calendar.unix: simplify current-timeval.
alien.data: <ref> doesn't need to zero memory.
io.encodings: string>byte-array-fast can use (byte-array).
ui.backend.gtk: connect ui signals before realizing the widget

gtk_widget_add_events() needs to be called before gtk_widget_realize()
otherwise oxygen-gtk will steal all lmb clicks