mleibman/SlickGrid — pull request #905 by gkostov (2014-03-19 09:52:49+00:00)
Title: Set null as the default for showHeaderRow

This update is to have `showHeaderRow` to default to `null` and setting it to `false` in the options to be a flag to render the header row but keep it hidden.
Currently having it `false` prevents the header row cells from being rendered and if you later call .setHeaderRowVisibility(true) you'll get an empty box with no cells in there.