for the efficiency check of the timing calculation, use a tighter margin than for the actual test itself

(checked by shane)

leftSplit() -> stripLeft()
rightSplit() -> stripRight()

This was mentioned as a comment in ticket #1721
http://bind10.isc.org/ticket/1721#no2

Also while here trivial date fix in stats manpage.

I didn't ask for review as this was trivial changes.

- split up split() into leftSplit() and rightSplit()
- made LabelSequence a Friend class of Name
   - no need for separate offsets vector
   - no need for Name::at_p()
- fixed copyright year :)

It did not make the tests fail, but it is still better not to have them
if they are not supported.

reviewed by zhanghaikuo

from vorner via jabber.

the rest of code actually didn't need this directive, so the removal shouldn't
do any harm anyway.

It is tomorrow.

use two tabs before the committer username.

lines too long.

use a tab before the keyword type.