[jboss-jira] [JBoss JIRA] (DROOLS-708) Add checkstyle plugin config that bans/reports tabs for indentation + fix current sources

Add checkstyle plugin config that bans/reports tabs for indentation + fix current sources ----------------------------------------------------------------------------------------- Key: DROOLS-708 URL: https://issues.jboss.org/browse/DROOLS-708 Project: Drools Issue Type: Task Reporter: Petr Široký Assignee: Petr Široký Adding checkstyle plugin config that bans the tabs for indenting should make it easier to detect these errors. We need to decide if the plugin should be on by default or executed on demand and if want to fail the build in case some violations are found.