Document transactional (ACID) characteristics on Android & other platforms

[brodycj]

For reference:

• https://www.sqlite.org/transactional.html
• https://en.wikipedia.org/wiki/ACID
• https://www.sqlite.org/howtocorrupt.html

SQLite should never lose data or otherwise suffer from corruption if used properly.

The standard android.database.sqlite implementation should also have these characteristics as well (ref: https://www.tutorialspoint.com/sqlite/sqlite_transactions.htm http://www.vogella.com/tutorials/AndroidSQLite/article.html#performance etc.), though I would rather find if this documented by the Android project itself. However some people reported in data loss on certain versions of Android in 2014/2015 in storesafe/cordova-sqlite-storage#193. For this issue I implemented an optional, potentially costly workaround of closing and reopening the database after every COMMIT (it should be after every write ref: storesafe/cordova-sqlite-storage#672).

This should already be documented to a certain extent. I expect to document this further after fixing storesafe/cordova-sqlite-storage#672.