Refactor database view with a QStyledItemDelegate

[kiozen]

Here is another one #951

This time it's the database view. It's not finished yet and there are some bugs. But already good enough to play with. If you switch to dev the header bar of the database will be a bit weird. The first column with icon and checkbox extends over the complete width. You have to resize it manually again.

As usual I am not very happy about my tool button icon. Maybe Mitxel has a better idea.

Anyways nice if someone tests. I would suggest to backup your database. There is nothing that should really hurt the database. But better safe than sorry.

[kkarsten62]

...
Anyways nice if someone tests ...

I am very interested in this new feature. However, I am currently away from home and will be able to start testing from the middle of next week.

[kiozen]

PR should be complete by now.

[eyzdh]

I like and works fine

[kiozen]

merged