Import CMake support from OPM-Core
This is OPM-Autodiff 0.1

We don't depend on any Dune modules.
First partitioning into source/examples/tests

Reorganisations are likely.
Move MRST example closer to actual example
Complete import of CMake support from OPM-Core
Ensure viscosity derivative is initialized.
Adopt imported build system to OPM-Autodiff specifics

Updated include statements &c to follow.
Fix inverted set of automated test cases.
Adapt to CMake-based build system.

Specifically,

  - #include <config.h> where appropriate (all .cpp files)
  - Adjust include statements to account for sub-directory locations
    of .hpp files.
Merge remote-tracking branch 'atgeirr/master'