1. Complete restructuring of the documentation to account for
GradientProblemSolver.
2. Update the version history to account for changes since 1.9.0.
3. Add links and document the various examples that ship with ceres.
4. Documentation for GradientProblem GradientProblemSolver.
Change-Id: If3a18f2850cbc98be1bc34435e9ea468785b8b27
The existing introduction was a bit redundant and also
was not really an introduction. Also updated the build
instructions to reflect the new reality on Mac OSX.
Also updated the beginning of the tutorial to be a bit
gentler and updated the history to be more consistent
Change-Id: Ife38c1949252cf9f4c6301856957f2d38365f313