Bugfix/detach grid

[radiolips]

Fixes issue in new code found by @jhpedemonte (thanks!).

[jhpedemonte]

This isn't fully working with latest code. Nodes are still deleted from DOM when doing a destroy(false).

It works fine with commit 9c01f02 (if I change removeAll(!0) to removeAll(!1) in gridstack.min.js) but fails with commit 85740de (& master). Trying to find out what changed in gridstack.min.js.

[jhpedemonte]

Hmm, wait, I may have the commits wrong. But definitely still an issue on master. Just trying to find out where things went wrong.

[jhpedemonte]

Seems to be caused by commit a33f046 (after manually patching gridstack.min.js to removeAll(!1)). Any idea why these changes would still delete nodes when calling destroy(false)?

[radiolips]

Okay, give it one more try. We had found a silly bug a few days ago when we were doing our unit tests. Unfortunately, it turns out that fixing that bug created a new one. I have fixed that. Thanks for your patience and thank you very much for tracking it down to that particular commit. A slight bit of a doozy, but now it should work.

For reference, removeWidget with detachNode=false was also broken. Both destroy as well as removeWidget should now work properly with detach false.