a duplicated code handling upvoting extracted to a single method
fixed typos in method name and javadoc
fixed Issue #35 limit upvote count as a simple mechanism to lower impact of scripting vote attack
+ only for issues in state approved for voting (ie those showed on the main voting page) can be upvoted
add duplicated ip addresses to voteList as we need to count how many votes comes from which ip address to do fraud detection