xmodal fixes: more sensible defaults for 'message' modals; focus is now set to topmost modal; presets for 'size' or 'kind' property: max, large, med, small, xsmall; preparing support for using HTML5 'data' attributes to configure modal (checks boolean as 'true'/'false' string).
Partial fix for XNAT-3195 (form still will not submit?); some cleanup on the new/edit subject page, but there's still a really strange bug that was there before but is more apparent now (bug report coming next); xmodal - moved modal .focus() to before .afterShow() in case another element needed focus instead; new subject pop-ups are now horizontally centered.