Useful for avoiding confusion when relocating database.
Changed the init method to initWithDatabaseAtPath which will allow us to override the sharedManager method in our unit tests and point to a test database
Reverse and improve commit 51e6da3
This optimizes speed : http://web.utk.edu/~jplyon/sqlite/SQLite_optimization_FAQ.html#transactions
SQLite is unable to bind a ? placeholder within an IN test : https://firstname.lastname@example.org/msg53802.html So we have to prepare the SQL statement ourself.