* Try to compile with GMP on windows and 32-bit linux
* remove leftover msys shell
* Don't use GMP Mersenne Twister, bad randomness and untested Nim wrapper
* properly cache nim
* fix path after cache
* run pacman in msys2 env
* rework msys2 ... again
* shell compat for file clearing
* shell compat try-again for file clearing
* force bash for clearing parallel builds on windows
* Use nimscript directly (why didn't it work last time?)
* Avoid IO redirection to support any shell
* Avoid IO redirection v2 to support any shell
* add debug data
* add debug again
* Introduce pararun, a parallel test runner to remove need of GNU parallel
* pararun: style
