Documentation/scheduler/sched-deadline.txt: Current runtime becomes remaining runtime

Signed-off-by: Luca Abeni <luca.abeni@unitn.it>
Documentation/scheduler/sched-deadline.txt: Improve the readability of an equation by introducing some spaces

Signed-off-by: Luca Abeni <luca.abeni@unitn.it>
Documentation/scheduler/sched-deadline.txt: Clarify when the admission control will surely fail

Signed-off-by: Luca Abeni <luca.abeni@unitn.it>
Documentation/scheduler/sched-deadline.txt: New URL for CBS Technical Report

Signed-off-by: Luca Abeni <luca.abeni@unitn.it>
Documentation/scheduler/sched-deadline.txt: Substitute "smallest" with "closest"

You can have a large deadline, but it could be the next one to trigger.

Signed-off-by: Juri Lelli <juri.lelli@gmail.com>
Documentation/scheduler/sched-deadline.txt: Rewrite section 4 intro

Section 4 intro was still describing the old interface (with meaningless
sentences :\). Rewrite it better.

Signed-off-by: Juri Lelli <juri.lelli@gmail.com>
Signed-off-by: Luca Abeni <luca.abeni@unitn.it>