Automatic conversion of text file attachments

When a text attachments is added to a email message, if the newline format is <LF> (typically in unix systems) is converted to <CR><LF> (typically in windows systems). If consumer of the txt file is a program that require a precise newline format, as for example shell scripts or CSVs, the resulting file will be corrupted by the conversion.

Steps to reproduce:

1. Create a new email message
2. Add a text file as attachment
3. Save the email message as draft and close
4. Open the draft email and download the attached file

Example

Before:

[amygos@Ono-sendai ~]$ echo test > test
[amygos@Ono-sendai ~]$ cat test | hexdump -C 
00000000  74 65 73 74 0a                                    |test.|
00000005

After:

[amygos@Ono-sendai ~]$ hexdump -C test 
00000000  74 65 73 74 0d 0a                                 |test..|
00000006