In Penknife, added `is-a-struct`. Refactored built-in function definitions. Fixed a potential bug in `set-impl` caused by having two JS variables named "args". Corrected an error message for `is-a-comparable-token` which called it "token-is-comparable".
In Penknife, added `is-a-struct`. Refactored built-in function definitions. Fixed a potential bug in `set-impl` caused by having two JS variables named "args". Corrected an error message for `is-a-comparable-token` which called it "token-is-comparable".

rocketnia/era-cene,era-platform/cene,era-platform/cene,rocketnia/era,rocketnia/era-cene,rocketnia/era,rocketnia/era,rocketnia/era-cene,era-platform/cene