String Theory 3.3

• Add support for }} as an escape sequence for literal } in format strings. This means that formatting a string with escaped literal {} characters can be balanced: ST::format("... {{some-uuid}} ...") => "... {some-uuid} ...".
  • Warning: This is a potentially backwards-incompatible change. If you already have format strings that contain a double }}, they will need to be escaped now (}}}}).
  • Note: There is no behavior change for a single } which is not already part of a format specifier. It will still be written as-is to the output, for backwards compatibility.
• Remove support for std::experimental::string_view and std::experimental::filesystem in favor of the non-experimental versions.
• Fix a unit test for compatibility with musl libc.
• Clean up a few unnecessary includes and no-longer used internal support macros.
• Fix a few minor issues identified by cppcheck.
• GCC: Only link to stdc++fs when it is required for using std::filesystem.