REST API: Add / fix content for port types
REST API: Add / fix content for port types

Content is taken from MidoNet v1.7 documentation. It got lost
during automatic conversion from reStructuredText to AsciiDoc.

Change-Id: I2bf05af09c3c9735d16d6b05507551f96cd69a24
Signed-off-by: Jan Hilberath <14e793d896ddc8ca6911747228e86464cf420065@midokura.com>

midonet/midonet-docs,yantarou/midonet-docs,yantarou/midonet-docs,midonet/midonet-docs,yantarou/midonet-docs,midonet/midonet-docs,midonet/midonet-docs