added config options group to doxygen
more doxygen comments added
In adjoint subsonic outlet bc: direct soln values using Reimann and c instead of c^2
added config options group to doxygen
more doxygen comments added
In adjoint subsonic outlet bc: direct soln values using Reimann and c instead of c^2
Merge branch 'develop' of https://github.com/hlkline/SU2 into develop
 addtl correction to psi_outlet[0] and addition of mass_flow_rate objective term to psi_outlet[0]
fixed typo
Merge branch 'develop' of https://github.com/hlkline/SU2 into develop_adjoint

Conflicts:
	Common/doc/docmain.hpp
	Common/include/config_structure.hpp
	SU2_CFD/src/solver_adjoint_mean.cpp