better T in grid/smartgrid

removed unused imports, fixes issue 1464 (wrong and missing T in grid and smartgrid), fixes issue 1465 (translation of "None" message).

It remains "unfixed" the point on issue 1465 on having an empty row shown in the table, but I'm not for it.

The fix would involve changing line 2429 from
htmltable = DIV(T('No records found'))
to
htmltable = DIV(TABLE(TR(), TR(T('No records found'))))