Added ex31 to TS - solution of the ODEs in Hull, et. al., SIAM J. Numer. Anal., 9(4),1972
Added problem class B to ex31
Added option to test convergence to ex31
Added a helpful comment
Few more useful comments
Useless - corrected an alignment thing
Added problems C1-C4 to ex31 and some other improvements...
Added definitions for implicit time-integration to ex31
Added some useful comments
Adding extrapolated initial guess to ARKIMEX - part 1
Adding extrapolated initial guess to ARKIMEX - part 2
Bugfix: do not use extrapolated initial guess in the first time step
Repositioned the saving of previous time-step stage values to after acceptance of time step
Ex31 made more generic from handling just Hull ODEs...
Added comments detailing all the cases coded in...
Fixed a bug in TSInterpolate_ARKIMEX...
Bugfix in TSExtrapolate_ARKIMEX used to calculate stage predictor-based initial guess...
Added IJacobians for Hull's problem class B, and some other small changes...
  Replaced math functions by their PETSc equivalent
Fixed two errors in ex20 so that it compiles and runs...