Fix eviction of saved password when saved encrypted on disk

Fixes issue #63:  https://github.com/bitboxer/chrome-passwordmaker/issues/63
Implement option to disable master password saving

This is realised by a checkbox in the "General options" page
that, once checked, sets the "Save password" setting to "never",
deletes a possibly saved master password from memory and disk
and hides the "Save password" field in the popup
Remove forgotten debug statement
Merge pull request #83 from oolongbrothers/disable-password-saving-option

Adds option to never save master password
add changes to changelog
Next version :)
Merge branch 'master' of github.com:bitboxer/chrome-passwordmaker
Adds feature to display the username in the popup and to fill in
user name field when "fillingfields".
This duplicates the feature of the old FireFox version of
Passwordmaker right down to using the same regex for the test as
to whether a text field is a "username" to be filled in. It satisfies
the requests contained in the thread for issue #81.