MFC SVN revisions 280310-280311,281160,281167,282443,283023,283288:
r280310: Whitespace cleanup(s)
r280311: Update copyright(s)
r281160: [mergeinfo only] Fix root encryption key permissions (see r281230)
r281167: [mergeinfo only] Unbreak ZFS+GELI install option (see r281230)
r282443: Add swap size sanity check (allanjude)
r283023: Skip adding swap to fstab(5) if unused (allanjude)
r283288: Fix a syntax error (allanjude)