Modernize: replace macros with inline functions

[GravisZro]

• Make sure all macros pass in all variables used (a mesh* type varaible (aka m) needs to be passed in for several)
• Rewrite macros as always inlined functions to ensure type correctness

[robinchrist]

Your PRs cannot merged without merge conflicts.

Perhaps a summary PR would be a sensible idea?

[GravisZro]

@robinchrist Generally people want fine grained PRs (to investigate changes) and then rebase each PR as needed to resolve conflicts. Anyway, if you want one large PR then I can make it that way.

[GravisZro]

@robinchrist Do you want me to combine these PRs into a single PR?