Add new settings dialog "Dialogs 3"

(fixes issue #1645)

Signed-off-by: Sven Strickroth <email@cs-ware.de>
Extend e5b2fb9dbe391a48845726555763b59aa280cf4f to arbitrary defaults

Signed-off-by: Sven Strickroth <email@cs-ware.de>
Add support for core.quotepath

Signed-off-by: Sven Strickroth <email@cs-ware.de>
Warn user before saving if source differs from destination store

Signed-off-by: Sven Strickroth <email@cs-ware.de>
Update changelog

Signed-off-by: Sven Strickroth <email@cs-ware.de>
Update Tortoise.pot

Signed-off-by: Sven Strickroth <email@cs-ware.de>