PUBLISHED_FROM=cf49d0d345e4a7607c535f9578b8ed4160f2fccd

Note: this is only the first step; the C sources won't be built until
the second step is done.

The actual build takes about 1.3s on cloud2 which still runs the docker
containers and image layers on the very slow spinning disk. cloud3 has
docker mounted on the SSD disk; measured speedups of 20-30%

PUBLISHED_FROM=c5acef1d64ebc8dca8ed31f51685c8b3090c5767

Remove the random() stubs from the codebase

PUBLISHED_FROM=0f56ec7dffa0af1f5061a17d8801239d6f0e32a5

Use the same config mechanism for ro_vars as for sys_config, get rid of a bunch of custom code.

PUBLISHED_FROM=d2be76cb97090669dd6a21e95d0ba821eaa1a313

PUBLISHED_FROM=de348f944de60d116d9d1f5d18e920991c811fa8

PUBLISHED_FROM=da1faa9b46cd0ff22dcba6d324b5847c4a0d42d8

PUBLISHED_FROM=f6679ea960b3aa0bc9142515548835ee0f78af67

PUBLISHED_FROM=a4666982707fcc96cfe6e75903cab9ac225351e4

Which disables tokenizer, parser, AST, and compiler. On ESP8266, it
frees 21K of ROM.

PUBLISHED_FROM=ff4c53ace6b9056c595b9e12ef3453330d659775

PUBLISHED_FROM=5dc567f8978d5414835f7a2338a78ae9eb683f55