check for network connectivity onCreate/Resume refresh
ManageBlogsActivity and SelectCategoriesActivity - check for network connectivity onCreate/Resume refresh
update categories each time the user load the select category activity
code style
fix #1797: refresh posts and pages when the activity is created
fix #1386
notify the user if he can't refresh posts list
null checks
refresh media grid onResume if list is empty and network available
restore local_changes string
reuse the old message when we prompt the user if he wants to overwrite local changes
remove toast notifying the user of aborted refresh
Merge pull request #1798 from wordpress-mobile/issue/1784-airplane-refresh-oncreate

fix #1784 airplane refresh oncreate