mdolab/dafoam: v2.2.6

This release fixed bugs and added new features. Fixed bugs for the actuatorDisk and actuatorLine models. https://github.com/mdolab/dafoam/pull/152/commits/db39fc48c0248e07cace46d89b772e5b8144db3f https://github.com/mdolab/dafoam/pull/152/commits/3cb219d4a27c708a7aa5aef12a4a4f4a5c01f405 Added a few transient solvers, i.e., DAPimpleFoam, DALaplacianFoam, and DAScalarTransportFoam Enabled the JacobianFree option for the hybrid adjoint Implemented the time accurate adjoint, but the derivatives were not accurate yet Fixed the missing ddtCorr term for DAPisoFoam https://github.com/mdolab/dafoam/pull/152/commits/916d7f72ae36e76d9fee1d8968e86d2ac0182be8 Change the DAOption interfaces for hybrid and time accurate adjoints Fixed a minor issue for the mean-field computation for unsteady solvers https://github.com/mdolab/dafoam/pull/152/commits/abe1afa555d660ff7a48f1c087d8f584f907248d Relaxed the tolerance for regression tests https://github.com/mdolab/dafoam/pull/152/commits/1eff9adfbd630b0c02e80b8934a96dadf7ac24bb Renamed objFuncHist.txt to objFuncTimeSeries.txt https://github.com/mdolab/dafoam/pull/152/commits/672f8bf2c380b9d870d3b4679e04ed91e8a47d0