Add fixes for multiple definitions of ERROR on Windows to docs.

- Explain the various ways to fix the problem of multiple definitions
  of ERROR from glog / miniglog vs windows.h.
- Add note about use of CMAKE_LIBRARY_PATH to aid FindBLAS & FindLAPACK.
- Fix minor style typo in code-block for sample Ceres output.

Change-Id: I21742614f4c5a8fe1ac8f66811b7777a72bcc503