Remove DAFFODIL_HOME since IDEs don't need it

- remove daffodilRoot, which uses DAFFODIL_HOME, as replacing it with "." is essentially a no-op in the Paths.get function
- update comment

DAFFODIL-2836

daffodil-cli/src/test/scala/org/apache/daffodil/cli/cliTest/Util.scala

@@ -58,10 +58,10 @@ object Util {
   }
 
   /**
-   * Convert the daffodilRoot + parameter to a java Path. The string
+   * Convert the parameter to a java Path. The string
    * parameter should contain unix path separators and it will be interpreted
    * correctly regardless of operating system. When converted to a string to
-   * send to the CLI, it will use the correct line separator for the
+   * send to the CLI, it will use the correct path separator for the
    * operating system
    */
   def path(string: String): Path = {