Scheduler activate root

Re-set the task waits on activation, saves a loop over the tasks in scheduler_start.

Added 23 commits:

• 823a065f...def34d3a - 21 commits from branch master
• df87333a - Merge remote-tracking branch 'origin/master' into scheduler_activate_root
• 58857257 - Remove unused function and recycle old name

Had a good look at this and it seems to be working, so will accept (just cleaned up an unused function and merged from master). My timing tests show that this makes the smallest time steps twice as fast for EAGLE_25 on 12 cores, will be interesting to see the scaling plots.

Status changed to merged

mentioned in commit 676e5761