Updated connection interface
Removed extra line
Restore the ability to easily override the compilers
Table prefix was added twice

If a table prefix was set in the database config, this code caused the prefix to be added twice: once here and once in the call to the database engine inside `DatabaseSessionHandler`. refs #4580 on the correct branch.
Merge pull request #4609 from kohenkatz/4.2

Table prefix was added twice
Merge pull request #4605 from GrahamCampbell/4.2-views

[4.2] Restore The Ability To Easily Override The Compilers
Merge pull request #4604 from GrahamCampbell/4.2-db

Updated Connection Interface
Stop using Whoops.
Work on error responses.
Quit overriding.
Increment version.
Work on Whoops.
Remove some unnecessary Whoops files.
Fix spacing.
Remove pretty page handler from compiled classes.
Increment verison.
Move array_* helpers function to Arr class
Convert call to array_helpers to static calls