screen comparison for hubs

POM update to selenium 2.43.1 + dependencies (apache httpcomponents)
test for comaring screenshot for hubs menu
please use URLBuilder for building URLs so tests can be run on different environments.

What is more, you can consider adding the possibility for passing wikiName from command line (for example if someone wants to run given test on different wiki than serowiec) and if wikiName is not passed you can fall back to "serowiec"