Database schema internationalization, step 5

Translate database schema (table and column names)
into English.

Step 5:
- translate the dns.p_dom (old: dns.dr_dom) table and column
    sort (old: tri)
- remove the never used roleweb column of dns.p_dom table
- translate the dns.hinfo columns text (old: texte) and sort
    (old: tri)
- translate the dns.zone* column gen (old: generer)
- translate the dns.rr_mx column prio (old: priorite)
- translate the dns.rr_relay_dom (old: dns.relais_dom) table
    and column prio (old: priorite)
- translate some CGI form parameters