Making all config options in CMake & SuiteSparse cleanup.

- Also marking all library and include directories found via
  find_library/path advanced (not directly visible in CMake GUI unless
  toggled to show advanced options).
- Updating documentation to reflect SuiteSparse requirements on Ubuntu
  and ability to control build options in CMake GUI.
- Splitting out all SuiteSparse related find_XX directives into a
  FindSuiteSparse script.

Change-Id: I0d69e02392ec547a7c365ba3e06f2ebc61cacf16
4 files changed