use more specific selector for comment score in commentNavigator popular

fixes #1526
parse comment score into number when fetching it, not when sorting it. efficiency!
Firefox: Tree Style Tab compatibility

Fixes #1447.
Merge pull request #1527 from CyberShadow/tst-compat

Firefox: Tree Style Tab compatibility
use jquery, not ugly parentnodes, to find containers for ignored user's comments/posts

fixes #1528

hope i didn't miss some edge case