New syntax
<import-factor> ::= from <peering-1> [action <action-1>] accept
<import-term> ::= <import-factor> |
<importexpression> ::= afi <afi> <import-term> |
afi <afi> <import-term> EXCEPT <importexpression> |
afi <afi> <import-term> REFINE <importexpression>
mimport: [protocol <protocol1>] [into <protocol2>]