Demos: Added panel styling demo. Fixes #5539 #5449 #5591.
Merge branch 'master' of https://github.com/jquery/jquery-mobile
Demos: updated panel open on swipe demo.
Demos: minor changes in panel styling demo
Demos: removed arrows from sections nav panel.
Demos: minor changes in global nav menu.
Demos: Added panel fixed positioning and responsive layout demo page.
Demos: updated panel demo page, linked to fixed positioning and responsive layout demo page.