Read program configs from environment variables #519 (#522)
Read program configs from environment variables #519 (#522)

* Read program configs from environment variables #519

* add more program config env vars

* add TI_LOG_LEVEL

* use arch_from_name for TI_ARCH (thanks to @yuanming-hu)

yuanming-hu/taichi,yuanming-hu/taichi,yuanming-hu/taichi,yuanming-hu/taichi