MultiDrag: Suggest to add oldIndices and newIndices in eventOptions

[runninghare]

At the moment MultiDrag plugin only added 2 extra eventOptions, which are very useful:

• items: an array of items being dragged
• clones: clones of the items

However if we take a look at the original properties, we would find oldIndex and newIndex are very important as well, especially for those data binding frameworks like Angular and React. However there are no counterparts in the multiDrag version.

At present I only tested angular-sortablejs which does not work with multidrag.

Suggested actions:

• Add 2 new properties in eventOptions: oldIndices and newIndices which allow data-binding framework to track where the dragged items come from and where they go to.

[owen-m1]

Done in commit 87c9a06.
I am only going to rebuild the scripts at release, so you will have to clone the repo and build it yourself if you want these options ASAP.

[runninghare]

@owen-m1 Thanks for your quick updates.