Merge branch 'hotfix/0.1.3' into develop

* hotfix/0.1.3:
  Correct option parsing for --euler, --rk2
Adding RK4
Update description of advance in lorenze help
Merge pull request #18 from trevilo/develop

Add RK4
Fix math in dox
Permit suppressing Doxygen \mainpage

When ar.hpp gets parsed by Doxygen within a larger project,
it can clobber the project's mainpage.  Permit suppressing
it by using something like

    PREDEFINED = AR_SUPPRESS_DOXYGEN_MAINPAGE

within a Doxygen configuration file.
Have best model correctly process AR(0)-only input

Root issue was an overzealous argument check.

Closes #21
Add PoF details and attribution suggestion
Merge branch 'release/0.1.4'

* release/0.1.4:
  Add PoF details and attribution suggestion
  Have best model correctly process AR(0)-only input
  Permit suppressing Doxygen \mainpage
  Fix math in dox
  Update description of advance in lorenze help
  Adding RK4