slight improvement in evaluator result descriptions
delete redundant mergeable.addDescription operation.
add target release attribute in Bug, add specified upstream organization/repository for different PRs
(due to PR descriptions redundant information: both wildfly and 6.x upstream PRs, both 6.2.x and 6.3.x Bz. we only collect correct upstream PRs and BZs base on upstream organization/repository,  current version and target release).
relocate regexp patterns from pull-processor Processor to shared part
allow to get converted flag value like "+, - ?" to friendly display
better exception catches in Bugzilla