DMDc implementation

[siuwuncheung]

This PR implements the DMDc algorithm (https://arxiv.org/pdf/1409.6358.pdf).

• A MATLAB script is added.
• The C++ implementation is added.
• An example of heat conduction with time-varying external inlet and outlet source is added.
• The control variables are the amplitude of the inlet and the outlet sources (where the location is fixed).

Sample runs and results for DMDc:

Command 1: mpirun -np 8 heat_conduction_dmdc -s 1 -a 0.0 -k 1.0 -visit

Output 1: Relative error of DMDc temperature (u) at t_final: 0.5 is 0.0021705658

Command 2: mpirun -np 8 heat_conduction_dmdc -s 1 -a 0.5 -k 0.5 -o 4 -tf 0.7 -vs 1 -visit

Output 2: Relative error of DMDc temperature (u) at t_final: 0.7 is 0.00099736216

[chldkdtn]

@ebchin @dylan-copeland