Database schema internationalization, step 11

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

Step 11:
- translate table global.nmgroup (old: global.groupe)
    and columns name (old: nom), p_admin (old: admin),
    p_smtp (old: droitsmtp), p_ttl (old: droitttl),
    p_mac (old: droitmac) and p_genl (old: droitgenl)
- translate matching indexes in tabuid() array
- translate table global.nmuser (old: global.corresp)

Note: column idcor is unchanged.