hygiene, clean up xmemmem() code a little, use xor sums

Signed-off-by: Sebastian Freundt <freundt@ga-group.nl>
Merge branch 'code/hygiene'

* code/hygiene:
  hygiene, clean up xmemmem() code a little, use xor sums
chore, change version number magic to yuck's scmver

Signed-off-by: Sebastian Freundt <freundt@ga-group.nl>
chore, stop checking for help2man

Signed-off-by: Sebastian Freundt <freundt@ga-group.nl>
Merge branch 'feat/go-yuck'

* feat/go-yuck:
  chore, stop checking for help2man
  chore, change version number magic to yuck's scmver