Remove 'col' from linters where it is hardcoded to 1 (#434)

* Remove 'col' from linters where it is hardcoded to 1

When 'col' is 1, the first column will get highlighted for no reason. It
should be 0 (which is the default).

In the scalac linter there was also a check about the outcome of
`stridx`. It would set l:col to 0 if it was -1, and then it uses
`'col': l:col + 1` to convert the outcome of `stridx` to the actual
column number. This will make 'col' equals 1 when there is no match. We
can remove the check because `-1 + 1 = 0`.

* Remove outdated comments about vcol

vcol was added as a default, and the loclists that follow these comments
do not contain 'vcol' anymore

ale_linters/scala/scalac.vim

@@ -23,13 +23,8 @@ function! ale_linters#scala#scalac#Handle(buffer, lines) abort
 
         if l:ln + 1 < len(a:lines)
             let l:col = stridx(a:lines[l:ln + 1], '^')
-
-            if l:col == -1
-                let l:col = 0
-            endif
         endif
 
-        " vcol is Needed to indicate that the column is a character.
         call add(l:output, {
         \   'bufnr': a:buffer,
         \   'lnum': l:match[1] + 0,