release lab04 type checking

info/labs/lab04/amyi.sh

info/labs/lab04/amytc.sh

info/labs/lab04/build.sbt

info/labs/lab04/examples/Arithmetic.amy

info/labs/lab04/examples/Factorial.amy

info/labs/lab04/examples/Hanoi.amy

info/labs/lab04/examples/Hello.amy

info/labs/lab04/examples/HelloInt.amy

info/labs/lab04/examples/Printing.amy

info/labs/lab04/examples/TestLists.amy

info/labs/lab04/lab04-README.md

info/labs/lab04/lib/scallion-assembly-0.6.1.jar

info/labs/lab04/library/List.amy

info/labs/lab04/library/Option.amy

info/labs/lab04/library/Std.amy

info/labs/lab04/material/NameAnalysis.md

info/labs/lab04/material/scallion-playground/build.sbt

...erial/scallion-playground/lib/scallion-assembly-0.6.1.jar

...b04/material/scallion-playground/project/build.properties

...ion-playground/src/main/scala/calculator/Calculator.scala