[Manager] Sort requests to suspend/resume/abort multiple tasks

[BrianNixon]

Resolves #1024 by making the Manager smarter when suspending/​resuming/​aborting multiple tasks at once.

When suspending or aborting multiple tasks, the requests are sorted to prevent the situation where as soon as a running task is stopped, a slot becomes free and the client immediately starts the next ready task, not knowing that the user wants to suspend/​abort that one as well.

When resuming multiple tasks, the ordering is reversed to favour resuming tasks that have already started over those that have not.

[davidpanderson]

I've taken to using e.g.
for (RESULT* rp: results_to_resume) {
...

[BrianNixon]

I got told not to use C++11…

[AenBleidd]

Thank you for the PR.

I got told not to use C++11…

I believe, in this case you can break the rule and use 'range-based for loop'. Just please don't use 'auto'.

I'll try to make a full review today later

[davidpanderson]

Now that we're using modern compilers on platforms we can use some C++11 features,
namely the ones that make code shorter and easier to read.

[AenBleidd]

Looks good to me. Thank you for the fix!