The CMake version is too slow when it must split strings
into tiny pieces for MSVC.

+ Note that this changes the paths to some generated headers so
  they match the location of their source data more closely.
+ Some uses of `smtk_encode_file()` or deprecated macros now
  use the new functionality to produce C++ functions, rather than
  string literals.
+ This requires changes to most contract-test repositories
  to update generated-header-file locations.