Merged upstream changes

BugFix: Now Shift+F3 and F3 search keys (and also Esc) work outside
SearchLineEdit widget.
BugFix: fixed freeze for install orphaned/yaourt package (thanks to
tbinkau).
BugFix: fixed notify-send code in octopi-notifier (thanks to vedgy).
merged upstream change
Refactored the packageView to use a single model.

Imho much better to read and build upon. Also it should be a bit faster.
reintegrate branch feature_pkgModel @21e9c87

- sorting first column
- first display of package tv
- concurrency fix for group members update
Merge remote-tracking branch 'upstream/master'

Conflicts:
	CHANGELOG
	notifier/octopi-notifier/mainwindow.cpp
	src/mainwindow.cpp
	src/mainwindow_transaction.cpp
	src/searchlineedit.cpp
Merge pull request #30 from tbinkau/master

Merge BIG changes in model...