Use class_exists() instead of extension_loaded() for checking SQLite

https://sourceforge.net/projects/adminer/forums/forum/1095138/topic/6780041
Don't convert columns which are not selected
Open full edit SQL with Ctrl
Revert indeterminate checkbox state
Use ellipsis in overflowed texts
Handle max_input_vars and generalize Suhosin compatibility
Order by auto_increment column by default
Display pagination on a fixed position
Delete confusing link to the last page
Plugin for displaying JSON data
Revert "Order by auto_increment column by default"

This reverts commit 79b61855e56c433b1bb8599e2c76d29f188df05d.
Handle empty integer values in SQLite export
Export SQLite indexes (bug #3609741)