BZ-996028, DROOLS-157: Fix compilation error of antlr 2.x removal. Upgrade stringtemplate from 2.3.1 to 4.0.7 (to avoid antlr 2.x dependency - since we use antlr 3.5)
(cherry picked from commit 1e1aef36f24208fe346f918db6c65f7a6903c382)