[vala] (6 commits) Non-fast-forward update to branch staging

[Rico Tzschichholz <ricotz src gnome org>]

The branch 'staging' 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:

  b88fa50... vala: No need to run return_type.check() twice for method
  1be3531... vala: More thorough check of ValueType and set CodeNode.err
  7fbc73b... tests/girwriter: Add missing type-argument
  2094ff6... tests: Add more "type-arguments" tests to increase coverage
  d3e5013... vala: Stricter check of type-arguments for non-external met

Commits added to the branch:

  db9e4ce... gee: Add missing type-arguments
  b67bb03... tests/girwriter: Add missing type-argument
  5ffd65e... tests: Add more "type-arguments" tests to increase coverage
  5155348... vala: No need to run return_type.check() twice for method
  ba0d8e9... vala: More thorough check of ValueType and set CodeNode.err
  b64faa4... vala: Stricter check of type-arguments for non-external met