Fix weird behavior of slug increments

Let's say we had two rows for a name mark, which then slugs was mark and mark-1.

Then when creating a new slug for a user with the name mark-1, then the slug should be mark-1-1, since it is the first of mark-1, but mark-1 is already taken.

But before it would set the new slug to be mark-3, which makes no sense.

Coding structure upgraded

Coding structure updated, nothing important.

Speed upgrades

Upgraded the speed for making unique slugs.

First release

First release