added <threadsafe> mandatory flag for deployment
variabilized d-wall.html, using voxxr-conf.js props
added sidenote to call `ant deps` on the first time before deploying to GAE, in order to copy libs to WEB-INF/lib folder
allowing to crawl multiple events at the same time (useful for devoxxfr + devoxxuk
added command line to easily push crawler's git subtree on heroku