extensions: move uisetup and extsetup to standalone functions
This is to make them wrap-able. chgserver wants to know if an extension
accesses config or environment variables during uisetup and extsetup and
include them in confighash accordingly.
#require test-repo
$ . "$TESTDIR/helpers-testrepo.sh"
$ cd "$TESTDIR"/..
New errors are not allowed. Warnings are strongly discouraged.
$ hg files "set:(**.py or **.txt) - tests/**" | sed 's|\\|/|g' |
> python contrib/check-config.py