Installation Guide is no more

Change-Id: Id0115092295d97fdb198421e5e9ca4409c3516d9
admin guide and user guide are now merged into one super-doc

Change-Id: I2ab5fbf77e9e27914c81624bf5dac99fa7ab173f
use middle dot for HTML title separator

Because I think Sphinx's default em-dash looks too fat and weird.

Change-Id: I9bca4942aa52f1c58cc58989dbef807e9a55d2f7
Merge changes I9bca4942,I2ab5fbf7,Id0115092

* changes:
  use middle dot for HTML title separator
  admin guide and user guide are now merged into one super-doc
  Installation Guide is no more