moved the coffeescript extension over from .cs to .coffee -- let's leave C# in peace. Changed array comprehensions to always return their mapped result, even when unassigned

examples/syntax_errors.coffee

@@ -0,0 +1,20 @@
+# Identifiers run together:
+# a b c
+
+# Trailing comma in array:
+# array: [1, 2, 3, 4, 5,]
+
+# Unterminated object literal:
+# obj: { one: 1, two: 2
+
+# Numbers run together:
+# 101 202
+
+# Strings run together:
+# str: "broken" "words"
+
+# Forgot to terminate a function:
+# obj: {
+#   first: a => a[0].
+#   last: a => a[a.length-1]
+# }