[glib] (10 commits) ...Merge branch 'fix_more_warnings' into 'master'

[Sebastian Dröge <sdroege src gnome org>]

Summary of changes:

  f2be8c7... Fix signedness warnings in gio/ginputstream.c
  401ff06... Fix signedness warning in gio/gkeyfilesettingsbackend.c
  2187406... Fix signedness warning in gio/tests/gdbus-proxy.c
  d255962... Fix missing initializer warning in gio/tests/gdbus-non-sock
  cb0b4b0... Fix missing initializer warning in gio/tests/gnotification-
  bac08a4... Fix several missing initializer warnings in gio/tests/gdbus
  f587095... Fix signedness warning in gio/tests/socket-common.c
  59acf69... Fix missing initializer warning in gio/tests/gdbus-example-
  e642562... Add extra documentation about the return values of g_seekab
  3e2f31c... Merge branch 'fix_more_warnings' into 'master'