Set additional option for this JsModal.
Valuable option are headerCss and label:
'headerCss' -> customize CSS class name for the header.
ex: changing color text for header
$jsModal->setOption('headerCss', 'ui blue header');
'loadingLabel' -> set the text loader value.
ex: changing default 'Loading...' for no text
$jsModal->setOption('loadingLabel', '');
'modalCss' -> customize CSS class name for the entire modal.
ex: making modal fullscreen
$jsModal->setOption('modalCss', 'fullscreen');
'contentCss' -> customize CSS class name for Modal content.
ex: making content scrollable
$jsModal->setOption('contentCss', 'scrolling');
Note: Default to 'image' for backward compatibility.
You can set option individually or supply an array.