db: auto increment reset
core: deleted files, switched to class definition
index: topic stuff added
Revert "core: deleted files, switched to class definition"

This reverts commit 1adb50c0d4520bce32cdfe4ad0f6ea4b1ce453c1.
classes: redefinition, fixes, addendums

Section: Added section class (just an empty file at the moment)
SQL: Fixed execution issue with the class, also added is() function to
"poll" the database for connection.
Topic: Switched to PDO.
Redefinition so that the folder is now named "classes" instead of
"core".