GPII-752: Add status messages to allow the user to know what's happening in the system

This pull requests adds status messages for:
 - Saving and thus logging in (PMT)
 - Loggint out in PMT
 - Saving and Applying in PCP
 - Making a change in the settings in PCP
 - Logging out from PCP

Currently, with this pull request the whole workflow of PMT & PCP is being described with short status messages.

It was decided in the comments of http://issues.gpii.net/browse/GPII-752 that the status messages will move along, in parallel with the functionality of both panels. Once another functionality part is added, the issue perhaps should be reopened to reflect the functionality improvement with another message.
@jobara the root of all this evil is obsolete junks of code left from merging with Chris' branch quite a while ago. For starters, here's the reason for the extra "onLogout" call we're currently having https://github.com/GPII/prefsEditors/blame/master/src/shared/adjusters/js/prefsEditor.js#L57-L59. And here is the reason for the extra onSettingChanged event being fired instantly after onLogout: https://github.com/GPII/prefsEditors/blame/master/src/shared/adjusters/js/prefsEditor.js#L60-L63. Since PCP's prefsEditor component is agnostic of the logged user, there's no need for it to store user's token inside the model, wich I've reflected in the last commit https://github.com/radmanovi4/prefsEditors/commit/0784aab47c9e6b126c426828818f102973ea6dd6.

It would be sensible to refactor the prefsEditors repo once all major issues are merged (or at least get finished functionality-wise), but I can't promise of having the time for it until the end of October. Anyway, you can have another look of the pull request, thanks.