Fix complex scaladoc links

[eruizalo]

Adding scaladoc links to high order spark functions breaks the doc. Here they are some examples:

• Related with #109:

  • org.apache.spark.sql.functions.array
  • org.apache.spark.sql.functions.transform
  • org.apache.spark.sql.functions.aggregate
  • org.apache.spark.sql.functions.filter
  • org.apache.spark.sql.functions.array_join

• Related with #138:

  • org.apache.spark.sql.functions.locate
  • org.apache.spark.sql.functions.split
  • org.apache.spark.sql.functions.to_utc_timestamp
  • org.apache.spark.sql.functions.from_utc_timestamp

Tag added for future fixing @todo scaladoc link