Removed the ability to switch between textual/graphical summary views

https://github.com/ManageIQ/manageiq/issues/817
Removed graphical summary helpers

https://github.com/ManageIQ/manageiq/issues/817
Removed dashboards variable from session

https://github.com/ManageIQ/manageiq/issues/817
Refactored summary views to render only textual version

I also converted all tabulators to spaces in erb files

https://github.com/ManageIQ/manageiq/issues/817
Removed obsolete graphical views and the images they use

https://github.com/ManageIQ/manageiq/issues/817