Restore subredditFrontPage keyboard shortcut, add to other pages

http://www.reddit.com/r/RESissues/comments/1rik2h/shiftf_not_taking_me_to_front_page_of_the/

Looks like the subredditFrontPage keyboard shortcut accidentally got nixed with the goMode change (afb1778).  This restores it and makes it functional on comments pages in addition to linklisting pages.