Improvements to Post admin list view.
Fixed up/down-voting for non-empty .post-vote elements. In other words,
clicking on the .answer-img-{up,down}vote element still causes an
up/down-vote to happen, whether that element has child elements or not.
Renamed the imgClassAnswerVote variable because it relates to both
Questions and Answers.
Merge pull request #249 from knowledgepoint-devs/modal

Fix up/down-voting whether the *-img-*vote-* element has children or not, plus improvements to Post admin list view.