MFC r306601:dumpon(8) appears to be present in FreeBSD 2.0.5,despite initial import of man page listed FreeBSD 2.1.PR: 212445Approved by: bcr (mentor)Differential Revision: https://reviews.freebsd.org/D8105
MFC r272746: Add an ability to set dumpdev via loader(8) tunable.MFC r272747: Revert r156046. We support setting dumpdev via loader tunable again. Also change default disk name to ada.