Prevent silent partial rejection of OTP patches
Prevent silent partial rejection of OTP patches

... by propagating `patch` exit status during `compile` hook.

* Capture [exit status of actual `patch`
  command](http://pubs.opengroup.org/onlinepubs/9699919799/utilities/patch.html#tag_20_90_14),
  for detecting not fully-successful application of patch;

  * This may be fine-tuned by capturing and logging `patch` stderr.

* Propagate intended exit status out of of escript, by reviewing [how
  to exit from escript with non-zero exit
  status](https://github.com/erlang/otp/blob/OTP-20.2/erts/doc/src/escript.xml#L150-L157).

aeternity/epoch,aeternity/epoch,aeternity/epoch,aeternity/epoch