Moving the option "select..." to the placeholder for the select dropdown
Moved "select.." option to the placeholder attribute for the snapshot creation page
Moved the option 'select...' to the placeholder attribute for the attach volume dialog
Unneeded chosen update for the attach volume dialog
Merge pull request #219 from eucalyptus/GUI-397

Gui 397 Move the option "select..." to the placeholder attr for chosen dropdown menus