Enhance the split screen posting mode

1. change the way preview works
2. allow for editing existing posts
3. when saving a post, allow for continue editing and saving

Change preview and save actions

Existing Actions

• split screen - typing on the left and preview on the right
• right-pointing arrow, switches to large version of single screen mode for typing
• left-pointing arrow, switches to split screen mode
• preview:
  • when in split screen mode, app remains in split screen mode
  • when in single screen mode for typing, the app switches to split screen to show the preview text
• when in split screen mode or in single screen mode for typing, and when the save button is clicked, the app switches to split screen mode

Change Actions To

• when in single screen mode for typing, and the preview button is clicked, only the large version of preview screen is displayed. do not switch to split screen mode.
• when in split screen mode, and the preview button is clicked, remain in split screen mode.
• when in single screen mode for typing, and the save button is clicked, remain in single screen mode for typing.
• when in split screen mode, and the save button is clicked, remain in split screen mode.

Files to move into production

• splitscreen.js
• BlogPreview.pm
• BlogUpdate.pm
• BlogAdd.pm

#todo
#junco