DAMON support

Bugzilla: http://bugzilla.redhat.com/2004230

Patches 1, 42 and 49 are preparatory patches.

Patches 17, 54-56 are selftest patches.

Patches 13-16, 21, 35, 38-41, 59, 69-72, 84 and 85 are documentation patches.

Patch 86 enables the necessary configs

Signed-off-by: Chris von Recklinghausen crecklin@redhat.com