packaging: establish hgpackaging package

Previously, contrib/packaging behaved as a root to a
package directory and we had a "packagingutil" module. As I
work more on packaging code, we'll want to have more code
shared between different packaging tools. I think it makes
sense to have a single package containing multiple modules
than multiple top-level modules.

This commit establishes an "hgpackaging" package by moving
the existing packagingutil code to it.

Differential Revision: https://phab.mercurial-scm.org/D6083

contrib/packaging/hgpackaging/util.py

@@ -1,4 +1,4 b''
-# packagingutil.py - Common packaging utility code.
+# util.py - Common packaging utility code.
 #
 # Copyright 2019 Gregory Szorc <[e-mail]>
 #

contrib/packaging/inno/build.py

@@ -87,7 +87,7 b' def build(source_dir: pathlib.Path, buil'
     for finding the Python 2.7 toolchain. So, we require the environment
     to already be configured with an active toolchain.
     """
-    from packagingutil import (
+    from hgpackaging.util import (
         download_entry,
         extract_tar_to_directory,
         extract_zip_to_directory,

tests/test-check-code.t

@@ -12,8 +12,8 b' New errors are not allowed. Warnings are'
   > -X hgext/fsmonitor/pywatchman \
   > -X mercurial/thirdparty \
   > | sed 's-\\-/-g' | "$check_code" --warnings --per-file=0 - || false
+  Skipping contrib/packaging/hgpackaging/util.py it has no-che?k-code (glob)
   Skipping contrib/packaging/inno/build.py it has no-che?k-code (glob)
-  Skipping contrib/packaging/packagingutil.py it has no-che?k-code (glob)
   Skipping i18n/polib.py it has no-che?k-code (glob)
   Skipping mercurial/statprof.py it has no-che?k-code (glob)
   Skipping tests/badserverext.py it has no-che?k-code (glob)

tests/test-check-module-imports.t

@@ -21,8 +21,8 b' outputs, which should be fixed later.'
   > -X contrib/debugshell.py \
   > -X contrib/hgweb.fcgi \
   > -X contrib/packaging/hg-docker \
+  > -X contrib/packaging/hgpackaging/ \
   > -X contrib/packaging/inno/ \
-  > -X contrib/packaging/packagingutil.py \
   > -X contrib/python-zstandard/ \
   > -X contrib/win32/hgwebdir_wsgi.py \
   > -X contrib/perf-utils/perf-revlog-write-plot.py \

tests/test-check-py3-compat.t

@@ -5,8 +5,8 b''
 
 #if no-py3
   $ testrepohg files 'set:(**.py)' \
+  > -X contrib/packaging/hgpackaging/ \
   > -X contrib/packaging/inno/ \
-  > -X contrib/packaging/packagingutil.py \
   > -X hgdemandimport/demandimportpy2.py \
   > -X mercurial/thirdparty/cbor \
   > | sed 's|\\|/|g' | xargs "$PYTHON" contrib/check-py3-compat.py