[pkg] Tidy substvars usage in control file

The documentation package was missing a Built-Using field to record
the provenance of the templates.

Empty packages or meta packages do not require Depends on a specific
Python version, so we can remove the relevant substvars.

--HG--
branch : 3.26

debian/changelog

@@ -6,6 +6,7 @@ cubicweb (3.26.12-2) UNRELEASED; urgency=medium
   [ Jérémy Bobbio ]
   * Switch to Debian source format 3.0 (quilt).
   * Specify priority “optional” instead of the obsolete “extra”.
+  * Tidy substvars usage in control file.
 
  -- Denis Laxalde <denis.laxalde@logilab.fr>  Fri, 12 Jul 2019 11:54:09 +0200
 

debian/control

@@ -166,7 +166,7 @@ Breaks: cubicweb-postgresql-support (<< 3.24.0-1~)
 Provides: cubicweb-postgresql-support
 Depends:
  ${misc:Depends},
- ${python:Depends},
+ python-cubicweb (= ${source:Version}),
  python-psycopg2,
  postgresql-client
 Description: postgres support for the CubicWeb framework (Python 2)
@@ -182,7 +182,7 @@ Section: python
 # postgresql-client packages for backup/restore of non local database
 Depends:
  ${misc:Depends},
- ${python3:Depends},
+ python3-cubicweb (= ${source:Version}),
  python3-psycopg2,
  postgresql-client
 Description: postgres support for the CubicWeb framework (Python 3)
@@ -249,7 +249,6 @@ Package: cubicweb-ctl
 Architecture: all
 Depends:
  ${misc:Depends},
- ${python:Depends},
  python-cubicweb (= ${source:Version})
 Conflicts:
  cubicweb-ctl3,
@@ -264,7 +263,6 @@ Package: cubicweb-ctl3
 Architecture: all
 Depends:
  ${misc:Depends},
- ${python3:Depends},
  python3-cubicweb (= ${source:Version})
 Conflicts:
  cubicweb-ctl,
@@ -284,6 +282,7 @@ Provides: cubicweb-documentation
 Depends:
  ${misc:Depends},
  ${sphinxdoc:Depends},
+Built-Using: ${sphinxdoc:Built-Using}
 Recommends:
  doc-base
 Description: documentation for the CubicWeb framework