Refactor roleBasedVote handler

[ab-10]

Currently the roleBasedVote is declared in demo (under RoleBasedVoteHandler) and analysis (under DictionaryClassifiers). There should be no voting logic included in demo, so the RoleBasedVoteHandler should be modified so that it uses functionality from analysis and analysis should be modified so that it can provide explanations for role based vote (similarly as is currently done in demo).