The --hive-drop-import-delims option should accept a replacement string

When importing data into hive, you have the option of dropping the hive delimiters in data fields. It would be more useful to replace the delimiters with a user defined string. Often times the dropped delimiters (like \n) are separating words. If I want to split on white space in my hive queries, I'll now get two words merged together. A more desirable behavior would be to replace it with a space. Making it user configurable will give the most flexibility.