Add an option to set a default password length

When the browser is in incognito (private mode) and/or data has been cleared (cache and cookies):
In the Length-box of the Password Generator-screen the (initial) value for the number of characters normally defaults to 14.

Add an option to set a user defined (initial) value for the number of characters, independent of data stored on client-side.
This way the default is kept, regardless the type of browser session and/or availability of data.

Setting a default password length to (eg.,) 16 characters, this will always result to this value.