Add ability to auto-detect line endings.

When a CSV is created on a Mac, the line endings aren't always used by
fgetcsv. We account for this by setting auto_detect_line_endings to true
in the PHP ini.

By using ini_set() this setting is updated for this script's run and
then set back to the standard PHP ini on the server.

The reason I added the $detect_line_endings param to get_array() is setting auto_detect_line_endings does come at a server performance cost. So, I think it makes sense to let the developer decide if it's OK to use for his application.