Added note to BibTex for Ammonia

Signed-off-by: Ian Bell <ian.h.bell@gmail.com>
Added docs to AbstractState

Signed-off-by: Ian Bell <ian.h.bell@gmail.com>
added visc and cond to keyed_output

Signed-off-by: Ian Bell <ian.h.bell@gmail.com>
Started with conductivity - implemented n-Hexane

Signed-off-by: Ian Bell <ian.h.bell@gmail.com>