* Correct wrong comment lookup
* simplify regex by excluding comment and string blocks before
* simpler lookup for each type
* update checks for more tests for various special cases
In DB IO
* add a function to return all placeholders found in a query
* only numbered parameters are looked up
Add more checks in phpunit for this,
Update the placeholder check and convert and move all regex into the
placeholder convert support class
Move $ placeholder count function to the SQL\PgSQL class
Note: further moves of PgSQL only stuff have to be done for SQLite
SQL class add
