Doc: CG - replace all references of Google Code (issue 294820044 by address@hidden)

[pkx166h]

Reviewers: ,

Message:
There are still 2 references to Google Code but they will be 'fixed'
with stage 2 of https://sourceforge.net/p/testlilyissues/issues/4794/

(else I'll end up with a merge conflict if I change it here).

Description:
Doc: CG - replace all references of Google Code

Issue 4672

Replaced all @urefs and
@examples with URLs from
Allura/Sourceforge.

Also modified some of the
notes in the Bug Squad
section to bring the
instructions up to date
with regard to how to
get an Allura account etc.

Added Ralph back to the
Bug Squad list.

Please review this at https://codereview.appspot.com/294820044/

Affected files (+85, -75 lines):
  M Documentation/contributor/administration.itexi
  M Documentation/contributor/doc-work.itexi
  M Documentation/contributor/issues.itexi
  M Documentation/contributor/source-code.itexi