MFH: r405234

• rework pkg-install and pkg-message [1]

• install postfix specific mailer.conf.postfix into DATADIR [2]

• use new notation instead PATCH_DIST_STRIP

• bump PORTREVISION

1. detect if the port is installed without TERM, in this case do not ask the to make postfix the default mailer and respect the env POSTFIX_DEFAULT_MTA. This helps tools like salt, ansible, cfengine and puppet during the first package installation.

2. $DATADIR/mailer.conf.postfix can be used by the tools in 1)

Approved by: portmgr (feld@)