Redraw for non-<expr> mappings
Use non-expr mapping for normal & visual mode

- TODO: handle stay command
Add comments for TODO of expr-mappings
Fix stay command for non-expr mappings
Fix histadd for non-expr stay command
Fix offset handling for stay command
spec: fix test cases

- skip offset suite because feedkeys() cannot be tested
doc: add note for <expr> mappings restriction for autocmd
spec: add highlight test
Fix non-expr mapping jump position
spec: fix to see does v:hlsearch exist
spec: add specs of dot-repeat
spec: add a spec of operator-pending behavior

- Skip because current Vim doesn't support any variables to fix it
spec: add TODO of register spec
Merge branch 'non-expr' into dev

- including adding and improvement of some specs
pseudo-normal-zz after scroll
Handle v:searchforward to handle `n` and `N`
Fix to use search flag for searchpos()
Fix to limit the `topline` value
Fix window scroll feature using appropriate sort()