- get_cells() FSM correctly treats unclosed quotes now,
- fixed gqq command: now it aligns all the table
- proposed 'fast' variant of gqq: gq1 that aligns current + 2 above rows
1. s:get_aligned_rows(): getting 2 last rows is enough for having been
formatted tables
2. vimwiki#tbl#get_cells(): using faster strpart() instead concatenating
every new character into variables cell and quote
3. checking by getline() whether the line was changed before setline()
does matter on slower computers