Nested transaction sample from Usage does not work for iOS

[brody2consult]

The sample from the Usage section is an excellent test of nested transactions. @marcucio did some good work to make this sample work with batching for the Android version. I also did a quick test to verify that this sample is also working with the real HTML5 SQL API in Safari (with sqlitePlugin.openDatabase replaced by window.openDatabase). However, the nested SQL command does not seem to be executed for the iOS version, which gives me confidence that it is written correctly and we should try to make it working with the iOS version as well.

I would like to do some of the Javascript cleanup first and then identify which mechanisms will have to be changed to get this working with the iOS version.

[brody2consult]

As it turns out, you have to turn off the batching optimization in the Android version of SQLitePlugin.js to get the nested transaction sample working on the Android version. A workaround is to simply create a new transaction inside the executeSql callback function to execute a nested SQL statement. This is now clearly documented in README.md so this issue is changed from a bug to an enhancement, with a lower priority than some of the other issues.