Move more commands into the settings file
Move some Windows special-casing out of the compiler
This is a little cleaner, and removes a barrier to cross-compiling
to/from Windows. There are a few more tools that still need to be
handled in the same way.
Add ar location and details to settings file
Add "C compiler flags" to settings file
I've made cpp_args include gcc_args. It effectively didn't before,
but seeing as gcc_args sometimes has -D flags in, I think doing so
is the right thing to do.
"perl command" should be perl, not gcc!
Rename "GCC command" to "C compiler command"
Makes it consistent with the existing "C compiler flags"
Move gcc's and perl's location to the settings file
They were hardcoded in Config.hs
Rename "extra-gcc-opts" to "settings", and start generalising it