Back In Time should not save unchanged settings

[Tomáš Pikálek]

Steps to reproduce:
 - add a local (it could be encrypted) profile X, select a directory in a removable media, schedule when the disk is connected (udev)
 - add another profile Y (local, ssh, should not matter)
 - disconnect the disk for profile X
 - click Settings, change something in the profile Y, click OK
 - an error pops about profile X (that it could not find the disk - could not find UUID, could not find encrypted directory and others), so you cannot save changes in profile Y (I had to remove profile X, change settings for Y and then add again X later, when I could connect the disk).

Suggested solution - add Apply button to the settings window and save (after clicking OK or Apply) only the settings from current profile. When the user changes the profile in this window, ask him if he wants to save current profile. Another solution would be to save only the changed settings (like not to rewrite udev script if the user does not change scheduling or target directory in that profile).

[Tomáš Pikálek (tpikalek)]

I forgot to write that I use 1.1.0~alpha05 (from PPA).