BugFix: mergeAjaxCallback events stacking

[Krnlsoft]

Scope

This pull request includes a

• Bug fix
• New feature
• Translation

The actual mergeAjaxCallback have some issues with events stacking,
causing events to stack and getting triggered multiple times,
this issue only happen when using mergeAjaxCallback = true or mergeAjaxDeleteCallbacks = true,

Specific code,
targFunc is stacked, because is returned from previous settings and then nested in the new function

            targFunc = settings[funcName];
            if (flag && typeof targFunc === "function") {
                if (flag === 'before') {
                    settings[funcName] = function () {
                        targFunc.apply(this, arguments);
                        srcFunc.apply(this, arguments);
                    };
                } else {
                    settings[funcName] = function () {
                        srcFunc.apply(this, arguments);
                        targFunc.apply(this, arguments);
                    };
                }
            }

Changes

I've made some private copies of the ajax settings to work with,
resetting them everytime a new merge occur.

Related Issues

If this is related to an existing ticket, include a link to it as well.

[kartik-v]

Thanks - can you submit a minified version of the JS file as well. You can do minification online via this site.