Bug 890225 - Made "Clear All" not visible when there are no notifications
Bug 912020 - Save to settings DB when leaving the panel
Bug 932250 - Write a test for context menu activity picker

Conflicts:
	tests/python/gaia-ui-tests/gaiatest/apps/ui_tests/app.py
Merge pull request #13188 from AndreiH/bug932250

Bug 932250 - Write a test for context menu activity picker
Merge pull request #12863 from tomleese/bug890225

Bug 890225 - Made "Clear All" not visible when there are no notifications, r=timdream
Bug 932795 - remove unused systemXHR permission. r=daleharvey
Merge pull request #12885 from crh0716/912020

Bug 912020 - Save to settings DB when leaving the panel r=evelyn
changed logic of is_app_installed, Bug #931865
Merge pull request #13293 from stupchiy/issue_931865

Bug 931865 - gaia test is_app_installed doesn't check the last page of apps