fix(DocAttribute): Do not treat "0" as an empty value in getOption() (refs #4945)
feat(DocHtmlFormat): Add `displayrowcount` option for array attributes (refs #4851)

`displayrowcount=n` accepts an integer `n` that specifies when the
array's row count is displayed:

    n <= -1 never display array's row count
    n = 0   always display array's row count
    n > 0   display array's row count if row count > n

Default value is "10".
Merge pull request #1260 from eguaj/3.2-A4851

feat(DocHtmlFormat): Add `displayrowcount` option for array attributes (closes #4851)(closes #4945)