Log Message:
Update pear-Net_SMTP pacakge to 1.6.0.

Release date: 2011-06-06 04:41 UTC
Release state: stable

Changelog:

- Adding a new command() method for sending arbitrary SMTP commands.
- More kinds of socket write() failures are now detected.
- Improved PEAR_Error internal handling. (Bug 18469)
- External authentication methods are now supported via setAuthMethod().
- Resource-based data streams are no longer terminated prematurely. (Bug 18563)