Fixes to allow for flexible desktop and workspace configuration
Further fixes for flexible layout
Enhancements for the ipg (IPython Notebook) module

- now it can read a startup file to rebind the UI, similar to the
    reference viewer
- it also reads a settings file to set viewer preferences
Merge branch 'master' of github.com:ejeschke/ginga
Merge branch 'master' of github.com:nabobalis/ginga