Reduce and reorder imports in Java templates

src/main/java/org/sablecc/sablecc/GenParser.java

.../java/org/sablecc/sablecc/analysis/DepthFirstAdapter.java

...g/sablecc/sablecc/analysis/ReversedDepthFirstAdapter.java

src/main/java/org/sablecc/sablecc/lexer/Lexer.java

src/main/java/org/sablecc/sablecc/node/AAlt.java

src/main/java/org/sablecc/sablecc/node/AAltTransform.java

src/main/java/org/sablecc/sablecc/node/AAst.java

src/main/java/org/sablecc/sablecc/node/AAstAlt.java

src/main/java/org/sablecc/sablecc/node/AAstProd.java

src/main/java/org/sablecc/sablecc/node/AConcat.java

src/main/java/org/sablecc/sablecc/node/AGrammar.java

src/main/java/org/sablecc/sablecc/node/AHelpers.java

src/main/java/org/sablecc/sablecc/node/AIgnTokens.java

src/main/java/org/sablecc/sablecc/node/AListTerm.java

src/main/java/org/sablecc/sablecc/node/ANewListTerm.java

src/main/java/org/sablecc/sablecc/node/ANewTerm.java

src/main/java/org/sablecc/sablecc/node/AProd.java

src/main/java/org/sablecc/sablecc/node/AProductions.java

src/main/java/org/sablecc/sablecc/node/ARegExp.java

src/main/java/org/sablecc/sablecc/node/AStateList.java