* Implement a '#' prefix for raw identifiers that may alias keywords
* Review comments
* Disallow hashless raw identifiers in interpolations
* Run clang-format
Fixes#669Closes#368Closes#624
Deprecate PRINTT, PRINTV, PRINTI, and PRINTF
Default STRFMT("%f") to 5 fractional digits like "{f:}"
Any use of string formatting will share this default