DNS views, part 18 (3 of 2...)

Issue #26
User interface: search

This commit improves user experience by
providing a new search keyword "mailrole:"
in order to specifically search for mail
roles.

This commit also provided the opportunity
to rework French message file.

Search
Followup to 916d882c4ad8706be0d350ea69cf6d223815714e

Fix a bug in the mod CGI script: the previous
commit introduced a bug where an alias was
detected incorrectly as a host, and thus the
edition page was presented to the user.

This commit changes:
- "mode" parameter of filter-views function was
    redefined in
	"host" (a FQDN to a "pure" host)
	"host-or-alias" (a FQDN to a host or an alias)
- del and mod CGI modified accordingly