[m2460] Get rid of bounding radius in GetNearPoint[2D] and ObjectPosSelector.

This changes how ObjectPosSelector is used. It changes the way how the
functions Object::GetNearPoint and Object::GetNearPoint2d behave.

So you need to check all places where these functions are used if they are
still used correctly. Especially check your scripts!

Based on cmangos/mangos-wotlk@2d034a24dd

Signed-off-by: Daniel S. Reichenbach <daniel@kogitoapp.com>
[m2461] Improve ObjectPosSelector

Now a spot already occupied by the searcher will be preferred.

Based on cmangos/mangos-wotlk@4e31279ea2

Signed-off-by: Daniel S. Reichenbach <daniel@kogitoapp.com>
[m2462] Improve handling of TargetMMGen.

This will have impact on Chase and Follow movement.

* Refactor code to check if a new position is required for the MMGen into the
  new function RequiresNewPosition
* Refactor code to get the current targeted distance into function
  GetDynamicTargetDistance
* Change ChaseMMGen (angle = 0.0f case) chase to best contact point, not zero
  angle.

Based on cmangos/mangos-wotlk@897ed8271d

Signed-off-by: Daniel S. Reichenbach <daniel@kogitoapp.com>
Fixed a few compiler warnings.

Signed-off-by: Daniel S. Reichenbach <daniel@kogitoapp.com>