implemented 'share on google plus' as a text link
fixed previous typo in archiveArticle method that's erroneously linking the action to bookmark instead; also changed article show page's archive and bookmark links from text links to buttons (so it's consistent when we turn the 'share on google plus' button on)
updated G+ share as a button
Merge branch 'dev' of github.com:ralphreid/feeds_app into dev