User should be hinted while editing character to not change it to another one after 1st level

[ivellios]

History of games (and adventures) played with the particular character is saved and thus creates a history of character. For that reason it should not be changed into another character after it for example died.

The only sensible reason to change character is to do on it's first level and only if the previous character didn't finish at least one adventure.

For now let's handle it softly by displaying appropriate message to the user when editing character. The message should be displayed between the character edit form (not create!) and save button.

The message should be as follow:
"Tip: If your character died after finishing at least one adventure, do not change it to another one. In the future it may not be able to play the same adventure again. Instead create a new one."

The last words: "create a new one" should link to character creation view.

The whole text should be written in italics.