Bug #35800 update connection-style (solid/dashed) when changing corresp. column

Description:
when a column, which references another col via FK, is added/removed from PK the line-style (solid/dashed) should be updated in the diagram accordingly (identifying/non-identifying)

How to repeat:
- import/create two tables like these:

CREATE  TABLE IF NOT EXISTS `table1` (
  `idtable1` INT NOT NULL ,
  PRIMARY KEY (`idtable1`) )
ENGINE = InnoDB;

CREATE  TABLE IF NOT EXISTS `table2` (
  `idtable2` INT NOT NULL ,
  `table1_idtable1` INT NULL ,
  PRIMARY KEY (`idtable2`) ,
  INDEX fk_table2_table1 (`table1_idtable1` ASC) ,
  CONSTRAINT `fk_table2_table1`
    FOREIGN KEY (`table1_idtable1` )
    REFERENCES `table1` (`idtable1` )
    ON DELETE NO ACTION
    ON UPDATE NO ACTION)
ENGINE = InnoDB;

- put the tables on a diagram.
- open table2 and add column `table1_idtable1` to the PK

now the connection-line between the tables should switch to solid as this is an 'identifying relation' then. and switch back to dashed when the column is removed from PK again.

workaround in the meantime: after changing the columns, remove one of the tables from diagram (without removing them from model!) and put it back in from catalog pane. then the lines ar re-created with correct style.

this works now (tested in SVN 3005)

Noted in 5.0.18 changelog.

The status of a connection line in a table diagram was not updated
when a foreign key relationship between tables was changed.