lineedit: change how cmdedit_set_out_char works

lineedit: change how cmdedit_set_out_char works

Rename two badly names functions, use "clear to end of screen"
to eliminate annoying problems with clearing wide/combining chars,
and such. Run tested.

function                                             old     new   delta
put_cur_glyph_and_inc_cursor                           -     124    +124
put_till_end_and_adv_cursor                            -      24     +24
input_delete                                         125     130      +5
Ceos                                                   5       4      -1
Ceol                                                   5       4      -1
input_end                                             24       -     -24
cmdedit_set_out_char                                 122       -    -122
------------------------------------------------------------------------------
(add/remove: 2/2 grow/shrink: 1/2 up/down: 153/-148)            Total: 5 bytes

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>