Tab count reflects the number of both top-annotations and replies.

Instead of the normal ```Total annotations``` format and the previous ```Top level annotations``` format, now introducing the ```"Total annotations"+"Replies"``` format, if this string is shorter than 5 characters, if longer we're falling to the old ```Total annotations``` format.
Font size changed from 13.1px to 12.1px

Fixes #671
Don't display reply number of the number of replies is 0
Tag label: restore font and move it to the middle
Merge pull request #718 from hypothesis/671-top-and-reply-for-tab-counts

Tab count now includes the number of both the source-level annotations and the replies