The build system now passes compiler directives based on the mode being build. By default data is stored in the source root (and this is encoded into the compiled binary). However, if building in user mode then data is assumed to be at the meson install prefix data directory
Rescaling a mesh by a linear transformation is a useful option so that we can start with a single "base" mesh and then rescale it to the dimensions needed for our problem. This commit adds the LinearRescale option too meshIO so that a unit sphere can be turned into a sphere of arbitrary radius (as an example).
