[vala] (7 commits) Non-fast-forward update to branch wip/tintou/dbus-proxy-set-interface-info

[Rico Tzschichholz <ricotz src gnome org>]

The branch 'wip/tintou/dbus-proxy-set-interface-info' was changed in a way that was not a fast-forward update.
NOTE: This may cause problems for people pulling from the branch. For more information,
please see:

 https://wiki.gnome.org/Git/Help/NonFastForward

Commits removed from the branch:

  0a3ed10... gdbus: Specify the `g-interface-info` of the GDBusProxy at 

Commits added to the branch:

  ab178ea... codegen: Include "glib.h" for G_BEGIN_DECLS/G_END_DECLS usa (*)
  d02167a... codegen: Correctly handle transformation of translated stri (*)
  3d77608... codegen: Use defintions of public header in internal header (*)
  9f32492... vala: Drop --use-header compiler option and enable it by de (*)
  e9c5f4a... vala: Warn about usage of override to implement abstract in (*)
  61e69f4... tests: Extend "DBus signals" test to increase coverage (*)
  7392951... gdbus: Use GDBusProxy API to set `g-interface-info` at init

(*) This commit already existed in another branch; no separate mail sent