Oracle: fetch release date and set type

and save them in cards.xml
Sets dialog: new columns and sorting

Added "order key", "set type" and "release date" columns
Use a proxy model to sort the table
made the dialog wider accordingly
Better handle the TK set used for tokens

Let oracle add a basic TK set in cards.xml
Unify all the code previously using the string literal “TK”
Sets window: implemented save and restore buttons
Fixed button labels
Fixed indentation
Merge branch 'master' into set_extinfo
Merge pull request #449 from ctrlaltca/set_extinfo

Sets handling improvements