Create fun_export.R

Apply a function FUN to a query and export it to a file. 
If dealing with large datasets, it´s sometimes easier to query the database in chunks, process each chunk and export each chunk to a file. I needed to do this and export the data to another database and couldn´t read the hole table in memmory
Create td_export.r

export teradata query to .txt file
Create td_fun_export

apply a function to query chunks while being exported to a file
Rename td_fun_export to td_fun_export.r
Merge pull request #3 from martinbel/master

fun_export.R