fa13090d20 contrib: Remove optimize-pngs.py script, which lives in the maintainer repo (MarcoFalke)
Pull request description:
Moved to https://github.com/bitcoin-core/bitcoin-maintainer-tools/blob/master/optimize-pngs.py
Bitcoin Core should focus on the full node implementation, not on scripts to compress png images.
This script is only used when new PNG files are added to the repo. This happens about once every two years. So fetching the script from the other repo should not be a burden, but removing it from this repo is going to cut down on the meta files we need to maintain in the main repo.
ACKs for top commit:
practicalswift:
ACK fa13090d20 -- `+0 lines, -82 lines` :)
promag:
ACK fa13090d20.
hebasto:
ACK fa13090d20, verified that script is already [moved](https://github.com/bitcoin-core/bitcoin-maintainer-tools/pull/56).
Tree-SHA512: 37d111adae769bcddc6ae88041032d5a2b8b228fec67f555c8333c38de3992f5138b30bea868d7d6d6b7f966a47133e5853134373b149ab23cba3b8b560ecb31
332f373a9d [scripts] previous_release: improve failed download error message (Sebastian Falbesoner)
Pull request description:
Currently, if the earlier release build/fetch script `previous_release.sh` is invoked with the option `-b` (intending to fetch a binary package from `https://bitcoin.org`) and the download fails, the user sees the following confusing output:
```
$ contrib/devtools/previous_release.sh -r -b v0.9.5
[...]
gzip: stdin: not in gzip format
tar: Child returned status 1
tar: Error is not recoverable: exiting now
```
This implies that the download worked, but the archive is corrupted, when in reality the HTML document containing the delivery fail reason (most likely 404 Not Found) is saved and tried to get unpacked. In contrast to wget, curl is a bit stubborn and needs explicit instructions to react to server errors via the flag `-f` (outputs error message and returns error code, ideal for scripts): https://curl.haxx.se/docs/manpage.html#-f
On the PR branch, the output on failed download looks now the following:
```
$ contrib/devtools/previous_release.sh -r -b v0.9.5
[...]
curl: (22) The requested URL returned error: 404 Not Found
Download failed.
```
ACKs for top commit:
fanquake:
ACK 332f373a9d
Tree-SHA512: 046c931ad9e78aeb2d13faa4866d46122ed325aa142483547c2b04032d03223ed2411783b00106fcab0cd91b2f78691531ac526ed7bb3ed7547b6e2adbfb2e93
