Rename members of connectivity struct.
Add support for array of string parameters.
Change d3q19 in unittests to gconn.
Start adding support for multiple fluids.
Add new field initial condition initRandomEquilibriumDensity.
Add Shan-Chen force.

Still needs to implement different interactions strengths.
Add colour field calculation.
Add dumping of force and colour (for two-component only).
Update main for testing Shan-Chen.