CG updates

[Phil Holmes]

I've updated the CG with some new stuff for the Bug Squad - mainly 
information requested by the current squad or where it seemed unclear what 
was meant - for example, the definition of "Regression" should now be more 
explicit.  It's currently in staging working through to master, but while I 
was doing it, I came across this:

"Check if the issue falls into any previous category given on the relevant 
checklists in Bug Squad checklists. If in doubt, add a new issue for a 
report." 
(http://lilypond.org/doc/v2.15/Documentation/contributor/adding-issues-to-the-tracker)

I'm not convinced this makes sense.  Should it say "Check if there is 
already a bug report for this behaviour" or somesuch?

I'd also like to make the Issues to Verify process clearer (I've already 
made some changes as above).  In particular, I want squadders to label any 
issue they can't verify themselves with a label such as Needs_dev_to_verify 
or something like that.  This will show they've looked at it and prevent 
other squadders wasting time on it.  Are there any objections to this?

--
Phil Holmes