Added routine to remove posts in blogs that are no longer followed
Removing posts in unfollowed blogs is now performed as part of the initial Reader update
Updated AppLog calls
replace hasActivity() by isAdded() (or isVisible() in a specific case: ReaderPostPagerActivity.java)
Merge branch 'develop' into issue/1565-remove-hasactivity

Conflicts:
	WordPress/src/main/java/org/wordpress/android/ui/stats/StatsBarGraphFragment.java
Merge branch 'develop' into issue/1565-remove-hasactivity
use _git submodule_ to manage modules
remove references to git repositories
update readme with git submodule help
remove unused submodules
Merge pull request #1653 from wordpress-mobile/issue/1652-use-git-submodules

fix #1652 use git submodules
Merge pull request #1650 from wordpress-mobile/issue/1565-remove-hasactivity

fix #1565: replace hasActivity() by isAdded()
remove useless readme paragraph
update to latest utils submodule
Merge pull request #1642 from wordpress-mobile/issue/1619-remove-unfollowed

issue/1619-remove-unfollowed
show a different error message when user doesn't have permission to view comments
show a different error message when user doesn't have permission to view pages
Removed player overlay from video thumbnails
Moderate comments for `Note` objects via the REST API.

Reason: There's a chance that a self-hosted site might not have been added to the app that we received a notification for so we won't have any of the site data/credentials to moderate the comment view XML-RPC.
Fixes forever 'Loading...' display for comments on self-hosted sites.

Use android tools for text placeholders in `comment_detail_fragment`