Revert "optimize post pre-loading"

This reverts commit 58a1c899bc2be8c09cc0d97e9fd8640209bb1555.
fix bug - support loading blog as part of latest post
group - enable option for enable/disable groups
fix bugs

1. use GetArticleInfo to refresh comment count
2. ReadNextArticle RaiseCanExecuteChange
fix bug - reset vertical offset for ImagePopupViewer
fix bug - update of post replies (not working)
fix bug - article list, first time loading 4, then 8
fix bug - load posts after enabling group_pano
fix bug - implement link in comments
diable group test menu item on mainpage
add comment count for articles
fix bug - fine tune comment count loading for articles
fix bug - add SV for settings page
fix bug for no connectivity
amend about page
fix bug - refresh comment count for posts
refine text
add repost count and comment count to weibo
various fix

1. imagepopupviewer: in failure, show (GIF?)
2. refine experience of 1st time group setup
3. fine tune article list loading number
4. fix bug on threading
fix bug - InvalidOperationsException, font size