Fix dot stuffing bug

[masamunecyrus]

See:
http://stackoverflow.com/questions/15224224/smtp-dot-stuffing-when-and-where-to-do-it
http://tools.ietf.org/html/rfc5321#section-4.5.2

According to the SMTP standard RFC 5321, section 4.5.2:

To allow all user composed text to be transmitted transparently, the following procedures are used:

• Before sending a line of mail text, the SMTP client checks the first character of the line. If it is a period, one additional period is inserted at the beginning of the line.
• When a line of mail text is received by the SMTP server, it checks the line. If the line is composed of a single period, it is treated as the end of mail indicator. If the first character is a period and there are other characters on the line, the first character is deleted.

The current version of sendemail DOES pad lines consisting ONLY of a single period (.), but DOES NOT pad lines that begin with a period with another period. The result of this behavior is that mails sent via sendemail are received with that first period truncated.

For example, if you send an e-mail with the body text:

.
.test

You will receive that e-mail with the following body text:

.
test

This bug is fixed by doing a regexp search for all lines in $message beginning with a . and replace with ...