Simple implementation of macro replacement in C++ backend
Refactor declaration data types to have dedicated lists for parameters and field declarations
Beginning of integration functionality in transport.h; can now instantiate model classes. Note - this version does not build.
Macro replacement with index summation functionality; this version builds.
Revise macro replacement functionality to implement proper 'summation convention'-like expressions
Change index replacement to numeric rather than stringized. Fix bug which caused spurious newlines to be inserted in .h output.
Make classes 'model' and 'canonical_model' templates. Move parameter handling into parent class 'model', since it should be common to all models we handle.
Added argument-passing option to macro substitution. Updated cpp_vexcl.h to use this for <number> type and field, parameter vector names.
Working integration of the background. Container object for background evolution and ASCII data table output.