REPL import warning; version info in CLI

Adds the ability to toggle result decoding in REPL. Adds several more
useful functions to the base library.

test/Spec.hs

@@ -468,7 +468,7 @@ baseLibrary = testGroup "Library Tests"
 
   , testCase "Concatenate strings" $ do
       library <- evaluateFile "./lib/base.tri"
-      let input = "lconcat \"Hello, \" \"world!\""
+      let input = "append \"Hello, \" \"world!\""
           env = decodeResult $ result $ evalTricu library (parseTricu input)
       env @?= "\"Hello, world!\""