Make slave mobs react to master's chase target

[skyleo]

Pull Request Prelude

• I have followed proper Hercules code styling.
• I have read and understood the contribution guidelines before making this PR.
• I am aware that this PR may be closed if the above-mentioned criteria are not fulfilled.

Changes Proposed

Make slave monsters chase after what their master is chasing, instead of merely following him until he attacks or uses a skill on a target.

That way if the master is immobilized during chasing,
the slaves will still continue to chase and attack once getting in range.

Before this fix Hunters could Ankle Snare Orc Hero for example,
making his slaves completely unresponsive for the trap duration.

Change has been tested and found to be working well

Issues addressed: None?

[HerculesWSAPI]

This change is 

[4144]

better squash fixup commit with actual commits with changes. I mean better not create separate commits with compilation fixes

[skyleo]

better squash fixup commit with actual commits with changes. I mean better not create separate commits with compilation fixes

Yes, those will be squashed, but for the review they're there atm, so people aren't confused by me rebasing and changing the history.
There will be only 2 commits at the end of this Pull Request.

[skyleo]

@4144 We're assuming safely at a few places that the master is of type BL_MOB in mob->ai_sub_hard_slavemob in those changes. If you know of cases where this is not the case, please tell me so I can modify the changes.

Also squashed everything reviewed so far, except for Removing trailing whitespace and a new suggestion that has been applied.

[skyleo]

Squashed all that needed to be squashed ~
Ready to be merged.