Localize help.php . Use 'drop' instead of 'remove' in Slony. Print strnever for all...

Localize help.php . Use 'drop' instead of 'remove' in Slony. Print strnever for all infinite (role and user) validities. Use 'altered' instead of 'updated' for roles. Remove redundant strings strargname, strremove, strrolename. Remove unused strings strcatupdate, strmaxconnections, strnodatabase.