Use generics in Grammar and related code

src/main/java/org/sablecc/sablecc/ComputeInlining.java

src/main/java/org/sablecc/sablecc/ConflictException.java

src/main/java/org/sablecc/sablecc/Grammar.java

src/main/java/org/sablecc/sablecc/Inlining.java