dialog.js for dialogbox control

JS core for dialogbox control
Merge pull request #112 from vabatta/patch-3

dialog.js for dialogbox control
update css for styling dialogbox control

Update css for styling dialogbox control
dialog.less for dialogbox control

dialog.less for styling dialogbox control
Merge pull request #115 from vabatta/patch-4

update css for styling dialogbox control
add dialog js, less, css