…when it is not desired
…vents after ajax reload
…AJAX so the field initialisation works.
… in $many_many relations which are no longer related to any subjects
…mitted in r71650
…se a simple queue management idea to keep only the latest ajax request is valid, ie, we abort all requests before the current request is submitted, so that there is only at most one request spanning in the client side, so no early request's response cover late request's response, also greatly enhance the performance of both sides, especially in case of complicated operations in server side and complicated post-events in client side.
By enabling the synch = ture in the ajax request, the tagfield didn't work well in case that the search in server side takes long time, it has 2 bad side effects, 1. a early request might return the response late, and hence, cover a later request's response. 2. the client side (browser side) fill with spining request. In addition, currently tagfield doesn't work with 'Backspace' key, this is because the delay is set to 300 in the jquery.tags.js for some reason. So we decide to apply a patch tag_asych_request to this field. This is submission for preparing to apply the patch, mainly a partial rollback of r67871
…trunk now uses this