Double speed of build by running both tasks in separate threads.
Review URL: https://codereview.appspot.com/7706046

git-svn-id: http://blockly.googlecode.com/svn/trunk@697 c400ca83-b69d-9dd7-9705-49c6b8615e23
Fix path issue in CSS.
Fix deletion ofter drag to flyout (issue 125).
Fix 'create do procedure' with arguments (issue 123).
Update wiki images with new dropdown arrows.
Review URL: https://codereview.appspot.com/7772043

git-svn-id: http://blockly.googlecode.com/svn/trunk@698 c400ca83-b69d-9dd7-9705-49c6b8615e23